Those can be handled in other ways. For instance, seal openings to the outdoors, keep the house clean so ants aren't getting food, lay out ant poison that they take back to their nests so it's more targeted, spray diluted citrus oils in the places spiders like to hang out since they don't like the smell, etc.

or encourage possums to go tick picking.

> you would have ants and spiders up the wazoo in the house.

The spiders are great, they control the flies and other pests. The ants are a minor annoyance.