Not something I've heard of before, but (grep grep) I can see why ants might not like it underfoot. Our neighbour suggested using peppermint oil as an ant-repellant, and that seems to have been successful; Herself even permits (nay, requests and requires) its use in the kitchen. My problem with it is that I can't stand the taste or smell of peppermint, a disability which I believe I inherited from my grandmother.