The Ants are back in my compost bin. Unlike last year when I panicked this year I have left them to get on with helping turn the waste into fabulous compost and have bought anew bin for this years waste.
A good philosophy!
If you do want to get rid of them, a couple of buckets of water on the compost heap might make it too wet for them. Another trick is to put down semolina, which the workers feed to the queen and it swells inside her and kills her. The nest then breaks up, though obviously the ants go somewhere else.
We had carpenter ants under our bathroom for several years. Wish I'd known about the semolina treatment then!