Last night my poor little piggie got his head stuck in the grid. They are not larger, or anything, than the recommended size. I don't know if he was trying to run from another pig or got scared or what but all of a sudden I hear these terrible shrieks coming from their toilet area, which is under the second floor and hard to see. I throw the second floor off and he's stuck down there, his poor little body is frantic trying to get his head out. I grabbed his body and calmed him down and tried to get his head out. I couldn't but he managed to. Anyway...he's fine, I took him to the vet and he's okay but my point is, be careful of these grids, they can get stuck in them.