a place i used to work had tons of it to make DI water but i have never seen it sold... it'd be good to put where ants can get into your house also yes? a place i used to work had tons of it to make DI water but i have never seen it sold... it'd be good to put where ants can get into your house also yes?Diatomaceous earth is sold almost everywhere that sells pesticides or hardware. Larger quantities are sold for swimming pool filters. Heck, people even eat the stuff.
I imagine you could spray it around your foundation and it would work.