The purpose of some insects

Haha that is true beyre, but think about what they eat - pretty much anything remotely edible or biodegradable, right? In the wild they thrive because they can and do eat all the things that most other organisms make it a point to stay away from. They're just opportunists - if they find a way into a house, it's like a free buffet. They can eat all they want, make all the babies they want, free of charge! No competition, no predators if they're good at hiding, and virtually endless supplies...unfortunately for the humans, hahaha.