We're getting some too, especially in the lawn. I'm going over with a lawn rake to keep the heaps down so that when we mow we don't get bare patches. If you do that the day before you mow and pour a good bucket of water into the ant heap when you've taken the top off they'll move on - but they'll reappear elsewhere - I think it's just one of those years.
We've also got them in the compost heaps, but the regular stirring up and aeration seems to deter them.
Where you really don't want them is building nests under your plants and in your pots - if keeping the soil/compost moist won't send them packing you can treat the garden with nematodes which are very effective