[SatinDoll]

This occurred in the Triassic, just as dinosaurs began to appear. This particular type of animal was a mammal-like reptile that was a plant eater.

Llamas and alpacas do this. Horses can actually be trained to do this, too. Leaving poo and urine in one particular place isn't that uncommon in the animal world.

[fieldmarshaldj]

Did they find the bones of early homosexual males lurking just outside the bathroom ?

[goat granny]

rabbits do it by nature, put a rabbit in a cage and he will defecate in the same place, then eat some of it for extra minerals needed. thats the only way they can digest them...also make great fertilizer for a small garden. My rabbit had a genetic defect that his teeth could not be worn down as with most rabbits that chew on things like wood. I had to catch him periodically and using nippers trim back the front upper and lower teeth or they would grow right through the roof of the mouth. It was not an easy job and took 2 of us to do the trimming. Holding a kicking rabbit is a beatch.

[EinNYC]

Geckos do it, too. My leopard gecko and Tucson banded geckos always deposit their wastes in a certain part of their terraria. Makes cleanup easier, that’s for sure.