Do Chickens Prefer Round or Square Roosts? What the Studies Found

Neither shape wins on its own. In the one study I found that let hens choose, they picked square or round roosts over triangular ones, and a big roost over a small one. Everything else I read says the width matters more than the shape. So does a top that’s flat with rounded edges, on a bar that doesn’t wobble. If you want one number, make it about 2 inches across.

I rewrote this page from 16 sources, and you’ll find every one listed at the bottom. Six are research papers on laying hens and perches, where somebody measured which perch the hens used or how hard it pressed on them. Extension guides from three U.S. universities, a Scottish technical note and the Poultry Club of Great Britain gave me the building numbers. For winter I read a reader’s tip in Mother Earth News, and I checked what a 2×4 really measures in the U.S. lumber standard. Most of the trials used commercial laying strains rather than backyard breeds, so take them as a guide for your flock, not a rulebook.

The short version.

• Shape. Square and round both beat triangular in the one preference test I found. Neither one beat the other.
• Width. About 2 inches (5 cm). The Poultry Club of Great Britain calls a 2-inch square bar with the top edges rounded ideal, even for bantams.
• Edges. Round them off. A Scottish technical note says there must be no sharp edges, and Oregon State says poles that are too small or too round can cause foot problems.
• Material. Go with wood. That note also says there’s some evidence clean PVC is slippery, and round metal was the least-used perch in a 2024 trial.
• Fixing. Screw it down tight. The same note says a perch that doesn’t sway may matter more than what it’s made of.
• Winter. A 2×4 laid flat lets a hen cover her toes with her breast feathers. It’s only a reader’s tip, though. I couldn’t find anyone who has tested it.

What the Hens Chose

The study people quote on this goes back to 1990. Muiruri and colleagues ran a preference test on hens and published it in Applied Animal Behaviour Science. I could only read its conclusion, on the Animal Welfare Institute’s Refinement Database, and here it is: “hens prefer roosts that are large [5 cm diameter] rather than small, and square or round rather than triangular in shape.” So the hens didn’t pick between square and round, and you don’t really have to either. What they turned down was the small roost and the triangle.

A 2026 study backs up the idea that shape isn’t the big deal. Ellis and colleagues raised 150 pullets from 2 to 13 weeks old with three round wooden perches from about ¾ inch to 1¼ inches across, and they moved the perches to new spots every week. At night the pullets showed no preference for any diameter. What they did care about was the spot: more of them kept choosing the location that faced into the pen. In the daytime, the white pullets used the medium and large perches more as they grew. If you’re raising young birds, that’s worth knowing: where you put the perch seemed to matter more to them at night than how thick it was.

Then there’s which perch hens actually use. Stratmann and Ringgenberg ran a 2024 trial that gave 15 pens of 20 hens one perch type each, from day one to 40 weeks. There were five types: square fiber, two mushroom shapes (one metal, one plastic) and two rounds (plastic and metal). The round metal perch got used the least. The mushroom metal one got used the most, but those hens also had the most health problems as they aged. The authors say every problem they saw was minor. Still, “used the most” doesn’t always mean “best” for your hens.

Jacquie Jacob of the University of Kentucky adds one more vote. If red mites aren’t a problem in your coop, she says wooden perches are the best option “because more layers use perches if the perches are square rather than round.” The chickens at the top don’t seem to mind a round pole, though. Look at the white one and you’ll see its toes curled right around it.

Pressure on the Keel

Here’s the part the round-or-square argument usually skips. When your hen sits down on a roost for the night, her keel, which is her breastbone, rests on the bar too. Pickel and colleagues measured that in 2011 with a pressure-sensing film. They put 36 laying hens on test perches at night, three shapes in three sizes each, plus several commercial perches. Pressure peaks on the keel came out about 5 times higher than on a single foot pad.

Shape made a difference there. On square perches the keel’s peak force was lower and its contact area was bigger than on round or oval ones, so the load got spread out, which is what you want under a breastbone. Feet were a different story. Standing hens had higher peak force on their foot pads on square perches than on oval ones. And in that first experiment, perch size didn’t change the peak forces at all. Their two soft prototype perches beat every commercial perch on the keel, which led the authors to suggest a soft surface might cut down on keel and foot pad problems. The way I read it, a flat top helps the keel and a rounded edge helps the feet.

Metal comes up again here. Jacob says European farms typically use round iron tubes to keep red mites down, but those perches carry a higher risk of keel deformations. Struelens and Tuyttens, writing in the journal Animal Welfare in 2009, recommend perch shapes that ease the pressure on the foot pad and the keel. So the square side of the argument has a point, as long as you round off the edges your hen’s toes wrap over. The hen in the photo above is walking along the board at the bottom of her pen, not roosting. No real photo of a hen asleep on a perch passed our photo checks this time.

Grip and Material

Grip matters as much as shape, and Struelens and Tuyttens put it plainly. Perch material and shape “mainly affect slipperiness and grip quality,” they write. In that respect they rate plastic and metal perches as inferior, and circular ones along with them. So if you’ve heard round is the problem, that’s only part of it. Plastic and metal are on their list too.

A Scottish technical note on perch designs (from SAC, the college that’s now SRUC) says the same about plastic pipe: “when clean, PVC presents a slippery surface which birds may find more difficult to use (compared with wood, for example).” It wants room on each side of the perch so your hen can grip without her claws getting trapped. It also says the ideal perch has no cracks where red mites can hide. Then it makes a point I wish more coop plans did: “Ensuring that the perch is firmly fixed (and not allowed to sway) may be more important than the material itself.”

Wobbling is something researchers can count, and you can watch for it in your own coop at dusk. Pickel and colleagues tried 60 Leghorn hens on nine round perches in 2010, three materials in three widths from 27 to 45 mm (roughly 1 to 1¾ inches). The hens spent a week on each perch, and the team recorded one night on the sixth day. Balance movements dropped as the perches got wider, and they were fewer on rubber than on wood or steel. The authors call balance movements maybe the most sensitive sign of whether a perch gives a hen stable footing.

Stratmann’s 2024 trial saw balance movements in more than half the walking bouts on perches, more of them at dusk and on the mushroom shapes. Oregon State’s coop guide sums up the material question in four words: “Wood provides ideal footing.” The photo above shows what’s doing the gripping, a scaly leg and toes spread wide on the floor of a pen.

How Wide to Go

This is where the sources line up best. Here’s each one’s number, so you can see how close they run.

• The Poultry Club of Great Britain: perches “2” wide with rounded edges.” For bantams too, it says “2” square (5cm) with the top edges rounded is ideal.” Its page on rearing young birds adds that perches at least 2 inches wide shouldn’t give you bent breastbones from a perch that’s too narrow.
• The Scottish note: 3 to 5 cm across (about 1¼ to 2 inches), with “a rounded profile with a flattened top.”
• Oregon State: poles of 1- to 2-inch square lumber “with the top edges rounded off,” because “Poles that are too small or too round may cause foot problems.”
• Muiruri’s hens: the large 5 cm roost over the small one.
• Pickel’s 2010 hens: the steadiest footing on the widest perch, 45 mm.

Put those together and 2 inches (5 cm) is your number. It’s the Poultry Club’s figure and the size Muiruri’s hens chose. It’s also the top of the Scottish range and Oregon State’s. The shape they describe matches too: square or flat on top, with the top edges rounded so there’s no sharp corner under the toes. Honestly, I’d call that the real answer to round or square. It’s a bit of both.

If you keep bantams, don’t give them a skinnier bar. “Even for bantams, perches should be broad,” the Poultry Club says. The boards in the photo above show how much stock widths vary, and that’s why the next section measures a 2×4 for real.

The 2×4 in Winter

Then there’s the flat 2×4, which is the winter version of this argument. The write-up I found is a reader’s tip in Mother Earth News from January 2013, sent in by Gretchen Anderson in Idaho. “If you have a narrow roost, swap it out for a 2×4, oriented on the 4-inch side,” she wrote. That way, she says, the hens can splay out their toes and roost “with their breast feathers completely covering their feet,” because exposed toes can lead to frostbite.

It makes sense, but I didn’t find a study that tested it, so I can’t tell you it beats a 2-inch bar on frostbite. What the extension folks agree on is dry feet. Kentucky’s guide says birds tolerate low temperatures “but only if dry,” and that perching gets them off the floor and keeps their feet dry so frostbite doesn’t set in. Jacob’s frostbite page says combs and wattles are the most at risk, and possibly toes, and that “coop management is the real key.” Deep litter bedding and a bucket water warmer do the job there, she says, with no outside heat needed. So before you swap boards, I’d take a look at your bedding.

So what does a 2×4 actually measure? Not 2 by 4. The U.S. softwood lumber standard (PS 20-20, published by NIST) puts a dry 2×4 at 1½ by 3½ inches. On edge, that gives your hens a 1½-inch top. Laid flat, it’s 3½ inches, wider than any guide above asks for. A 2×2 is 1½ inches square, and a 2×3 laid flat gives you 2½. No standard board comes out at exactly 2 inches, so you’re picking a side of it. Those sizes are my math from the standard’s table.

Here’s how I’d use that. A 2×4 on edge with its top corners rounded sits inside Oregon State’s range and the Scottish one, just under the Poultry Club’s 2 inches. If your winters get bitter, flipping it flat for the cold months is a cheap thing to try. Just know it’s a keeper’s tip and not a tested one. Our How Cold Is Too Cold for Chickens checker can tell you whether tonight’s low is worth worrying about, and our post on chicken coop insulation ideas covers the rest of a winter coop. The shed above is just a shed, by the way, not a coop. No real photo of a coop in snow passed our checks.

Building the Roost

Once you’ve got the board, the guides mostly agree on where it goes. They don’t match on every number, so here’s whose is whose. Where they disagree, I’d follow the guide written closest to where you live.

• Height. Penn State Extension says 18 to 24 inches off the floor for standard chickens and 12 to 18 for bantams. It also says no chicken should perch more than 4 feet up. Oregon State says 2 feet, and just 1 foot for silkies. Kentucky allows 16 to 40 inches. The Scottish note puts the first perch at 45 to 60 cm (about 18 to 24 inches) and the top one no higher than 1 meter where it can. Jacob suggests about 3 feet for the lowest perch.
• Room per bird. Penn State gives 6 inches a bird, or 4 for bantams. Oregon State gives 5 to 10. The Poultry Club wants at least 9 for large fowl and 6 for bantams. Kentucky gives about 12, and more for bigger breeds. UK rules for laying hens ask for 15 cm, about 6 inches.
• Spacing. Penn State and the Poultry Club both say about a foot between perches. The Scottish note says at least 30 cm in all directions, and Oregon State says 10 inches. UK rules want 20 cm (about 8 inches) from the perch to the wall. Kentucky says at least a foot from walls and other perches, and not over feeders or drinkers.
• Heavy birds. The Poultry Club says heavy breeds should have low perches to avoid bumblefoot. Penn State says large meaty breeds shouldn’t get perches at all. Our Buff Orpington vs Jersey Giant post has more on roosts for a very heavy hen.
• Nest boxes. Keep the roost higher than the nest boxes, or the Poultry Club says your hens will roost in them.

Then build it the way the sources describe. Cut the bar from square-edged wood. If you’re using a 2×4 on edge, round over the top edges, then sand off anything sharp. Screw it down firmly so it can’t sway. Leave clear space on each side so claws don’t get trapped, and skip cracks where red mites can settle in. The Scottish note also wants a perch that’s easy to clean. If you’re working out how many feet of roost your flock needs, our Chicken Coop Size Calculator does the roost length along with the coop floor. For more layouts, see our chicken roost ideas. The beams in the photo above are square-cut timber, the kind of stock a roost bar starts out as.

So, round or square? I’d stop asking it that way. Give your hens a bar about 2 inches across with a flat top and rounded edges, fix it solid, and put it where they’d like to sleep.

Sources

• Muiruri and colleagues, Preferences of Hens for Shape and Size of Roosts (Applied Animal Behaviour Science, 1990), on the Animal Welfare Institute’s Refinement Database.
• Pickel and colleagues, Pressure Load on Keel Bone and Foot Pads in Perching Laying Hens in Relation to Perch Design (Poultry Science, 2011).
• Pickel and colleagues, Perch Material and Diameter Affects Particular Perching Behaviours in Laying Hens (Applied Animal Behaviour Science, 2010).
• Struelens and Tuyttens, Effects of Perch Design on Behaviour and Health of Laying Hens (Animal Welfare, 2009).
• Stratmann and Ringgenberg, Perch Shape and Material Affect Perch Use and Health Parameters of Laying Hens During the Rearing and Laying Phase (Journal of Applied Poultry Research, 2024).
• Ellis and colleagues, Layer Pullets Prioritize Roosting Location over Perch Diameter at Night (Applied Animal Behaviour Science, 2026).
• SAC Technical Note TN598: Perch Designs for Extensive Systems (PDF, March 2007).
• Jacquie Jacob, University of Kentucky, on the Poultry Extension site: Perches in Housing for Small and Backyard Poultry Flocks.
• Oregon State University Extension: Living on the Land, Backyard Chicken Coop Design (EC 1644).
• The Poultry Club of Great Britain: Housing, Equipment & Feed.
• The Poultry Club of Great Britain: Hatching, Rearing & Care of Young Poultry.
• Jacquie Jacob and Tony Pescatore, University of Kentucky: Properly Maintaining a Backyard Poultry Facility (ASC-246, PDF).
• Penn State Extension: Small-Scale Poultry Housing.
• Jacquie Jacob, University of Kentucky, on the Poultry Extension site: Frostbite in Chickens.
• Gretchen Anderson in Mother Earth News: Brrr! Quick Tips for Wintering Hens (January 23, 2013).
• NIST: PS 20-20, American Softwood Lumber Standard (PDF).

Sources checked October 27, 2026. The inch conversions and the board sizes are my math from the sources’ own numbers. We aren’t vets. If a hen looks sick, call a vet who sees poultry.

Related read: How to Raise Chickens for Eggs — Instant PDF download. Secure checkout by Stripe