Ants
They can be a pain when they start to ingress indoors, however they are fairly easy to control as a DIY`er.
Boiling water will only kill the top few hundred of the nest, which is a bit pointless when you consider each nest contains many thousands of ants, the rest will still be there waiting to carry on where they left off.
By far the better method is to use a liquid insecticide and dilute according to the instructions and spray along the wall and let it soak down into the ground. This treatment looks better than powder outdoors and soaks into the nest areas. A few treatments throughout the warmer weather may be required but if copious quantities of liquid is sprayed over a decent sized area beyond the nesting point there should be very little problems after treatment.
If however if the ants are indoors there will certainly be an entry point from outside, normally directly through the wall behind where the main activity in the room starts.
The easiest method of treatment is to spray the outside as previously stated, and then after sucking a bit of ant or insect powder up the vacuum nozzle to kill any ants that are sucked up, vacuum the area inside where the ants are travelling, follow them from where they start to where they finish, this can be quite some considerable distance, but persevere and suck up as many as possible. After this treatment return to where they were first seen and pull back any carpet and underlay until you see the end of the nest, which will almost certainly be between the floor and carpet as well as the underlay. Vacuum the area ensuring that you vacuum under the skirting board.
After the area has been vacuumed and the ants entry area has been found, lightly sprinkle some dust over the floor ensuring that some is under the edge of the skirting boards, which is where the ants will use as their road system from one area to another.
Replace the underlay and again give a very light dusting along the edges before replacing the carpet.
After this has been carried out do not vacuum too near to the edges of the carpet for as long as can possibly be avoided or else the dust will come through the carpet into the vacuum cleaner. Once all of the work has been completed take the vacuum outside to the dustbin and empty it. Do not bring it back indoors until it is empty or any surviving ants are likely to come back out through the pipes and start a new nest.