They do have holes for drainage but if sized properly for the snake's size, I don't think it is possible for their head to fit into those small drain holes. In my case, I just sorted through the mountain of pots and picked the numerous sizes that would work for my various sized animals. My group only ranges from about 120 grams to 900 grams now so it wasn't very large pots. They had some much bigger. They were all scrubbed clean in chlorox and water mix 50/50 so VERY strong then cleaned again afterwards with a milder disinfectant.