ant problems

There has been a huge upsurge of ants in recent years, don't know why. I have found that sprinkling polenta or maize meal mixed with a bit of icing sugar round the nest area has helped. The theory is that the workers take this to the Queen but she can't digest it and dies leading to the end of that nest. There is a nematode on sale now which if it is anything like nemaslug should be effective.