Ants are crawling around our house

A simple and amusing trick is to place a small, thin ring of something sweet, such as strawberry jelly, on the floor. In the middle of the ring, place some baking soda.

The ants will be drawn to the jelly, en masse. But baking soda takes on the scent of foods around it, so when the ants eat through and over the jelly, they'll continue and consume the baking soda as well. This causes their tiny, little thoraces to burst, effectively killing each ant that flocks to the jelly.

All that remains to be done is to sweep or mop up the remnants.

I've also heard that liberally applying hair spray to the foundation of one's house will go a long way toward deterring ants and other invaders. I did it once and it seems to help. It's also quite effective at withering clinging ivy.

Jam it back in, in the dark.