Fruit Flies

Although fruit flies have an insane repopulation speed, they can't just manifest out of thin air.

Once they do arrive, they'll however spread like crazy if they're able to find any kind of rotting material.

One of the main way they'll get into your home is actually through your food. Adult fruit flies will sometimes lay their eggs inside fruits and vegetables. Just think of it as a bit of free extra protein.

You do however need to make sure you consume your food before they hatch or you'll have issues.