So everything in the garden is looking lovely, the roses are flowering, the clematis are out, the delphiniums amazingly haven't been eaten by slugs. The only problem is pigeons. We had a resident pair last year, but now they seem to have multiplied with up to six pecking at the lawn. The lawn is now covered in pigeon poo, and you can't even put a picnic blanket down. My two year old loves rolling around on the grass and that's proving hazardous! There is a lot of clover in my lawn, is that what they're after, should I put some weed killer down?