Couple of years ago I had red ants in compost bin.

Make a tea of chillies. Just as you would make usual tea but using any kind of chillies...hotter the better I suppose. I only had the red dried at the time and so used these. Also I heated it all up in the microwave.
Let it cool and then 'water' the compost. It works.

Am gonna use this concoction to sort the ants out around the paving and damp course of my house as I wouldn't be able to use the commercial brands because of the birds feeding on the ants.
Starglo