Red ants

Red ants are an absolute nightmare on my plot and, I hear, all around the allotment site. 

I'm constantly finding nests in areas where I've used woodchips, or parts of the plot with couch grass, but I hate finding them in the winter - it's really bad, sting-ey news for the spring!

Pesticides aren't an option for me so all I can do when I find nests is leave them exposed and hope the birds will come for a snack...