I could leave mine - I have an old dog kennel with vinyl on the floor, and straw, and a removable roof, with a great dane sized dog cage attached to it. They can come and go anytime they want, the plastic floor can be hosed down, and in the morning they are let out into their own little paddock, but I could equally leave them in there all day or even a couple of, days if they were left enough food and water in such a way that they couldn't spill it. Mind you I only have 3 ducks and a drake.