So around where I live, everyone has a big problem with little sugar ants (we call them piss ants) getting into the gouse and ruining everything and just being nasty. Ant poison works, but they always end up coming back and it isn't safe for pets to be around it.
So here's what I found out. Ants hate cinnamon. ("Tigers love pepper, they hate cinnamon." ..anyone?) It won't kill them but they won't go near it. So what I did, was I put cinnamon on the window sills, everywhere I've seen them and don't want them. I also put it around the sink because they like to hang out around there.
Lucy won't eat it, but it also won't kill her if she does.
Thought I'd share.
I also think that pepper works too, but I haven't tried it.