I've used thick plastic halloween serving bowls(they are purple with black spiders on them). Just solder an entrance in the side and voila, a nice hide that is easy to clean. They were $1 apiece. I've also used washed, single-serve food trays(the black ones). The snakes seem to like them. I've also used the black containers from Chik Fil-A that the caramel sauce comes in and the big containers that the fruit salad comes in. Black, plastic and easy to clean.