i keep all my snakes i nthe same sized tub cause I don't have a mutli sized rack I just clutter up the tubs foro the smaller guys. I used a taper drill bit to make my holes inthe tubs they start at a1/8 up to 2/3 on the same bit and the holes are clean. I suggest starting with about 6 hold to allow air to move depending on how you set the tub will help set the hole were. I got a couple tubs I need ot tape hole up cause I loosing all my humidity thoughthem.. electric heat drys the air fast.