Exodus 8:3, 21

So the river shall bring forth frogs abundantly, which shall go up and come into your house, into your bedroom, on your bed, into the houses of your servants, on your people, into your ovens, and into your kneading bowls.

Or else, if you will not let My people go, behold, I will send swarms of flies on you and your servants, on your people and into your houses. The houses of the Egyptians shall be full of swarms of flies, and also the ground on which they stand.