dont let them go back into human form before digestion is over though, something bad could happen

One of my long standing house rules when I'm DM is to let people just be as creative as they want during downtime, as long as it doesn't affect the story. Druid wants to spend all day wild shaped as a turtle, hanging out in the pond? Sure, go for it - I'll ignore the X/hours per day limits or whatever. The wizard wants to cast Wish just to create a sick looking pipe to smoke from? Amazing, no XP or gold cost for that. Fighter wants to use Action Surge repeatedly to chop an entire tree into firewood for their winter log cabin? Don't forget to mount a deer's head above the fireplace.

me right now: 😯🐜🐜🐜🐜🐜🐜

As you begin devouring your unfortunate victims you start to feel strange. It turns out this ant colony is a race of highly intelligent multi-dimensional beings with psionic powers. Roll for initiative.