A few years ago I had a great time listening to my Grandad and his neighbour in rural Kentucky reminisce about how they used to deal with ants and other bugs getting into their homes.
Just sprinkle a line of DDT all around the building's foundations!
They claimed it even worked for mice
Gill, where are the ants coming from and where abouts are they a problem? There are some products that work great on nests that you can find, Nipon ant powder works great if you can get it into or around the nest, say if its under easily raised paving, or in the flower bed. There are some liquids that can be put on a bit of glass which ants take back to the nest, that works pretty well in the house. Not so sure about the ant traps, maybe I have just seen so many that were old or badly placed
Boiling water only works on contact and only really works outdoors. It is quickly cooled by contact with soil and there is nothing to stop the ants coming back to re-build the nest if you don't get them all. If the nest is among plants the hot water kills those very well!
The last thing, if the ants are getting in-doors, why are they coming in? Is there food, or are they just getting lost?
Hope you get it sorted. I had hoped it might be too early still to start worrying about ants