Chickens & hares collision boxes are too big

Small livestock like chickens and hares are often raised in small cages, but in game they can't stay inside because of their too big collision boxes. Instead, they teleport frequently to the upper level

For example, on this unfinished chicken coop (image & blueprint below) I have created 10 nest boxes. I can place chickens on the upper level just under the roof, but not on the lower one, even though they look big enough.

The question is not the well-known teleportation issue - it's the least bad behavior in such cases - but the minimal free space around the chicken to avoid triggering that. This free space is usually defined by an invisible collision box: I hope for a smaller, more precise one.

Other animals are probably affected too, but it's especially bad actually for small animals (hares & chickens).