A nest i made for my Ants.
This has a fitting for 100mm X 100mm at 3mm thick acrylic (not printable) and still leaves a 2mm gap for the lid to fit on top snug.

It has 3 openings on the bottom that will be where the cotton goes along with my "Base for Ant Nest V2" for keeping the humidity up in some areas while others stay bone dry.

the front ports fit a 16mm test tube snug and has a stopper so it doesnt just push through all the way. small ramps on the inside help ants to get up to the holes.

NOT made to consider heat mats/cables, but possibly will work if printing in ABS, unsure how the humidity will fair with heating as theres not much in terms of aeration.