Hi, if you don't know where the nest is, just give a good dose of ant powder where you see the ants, these will get covered in the powder and take it back to the nest, helping to kill more of them, but having said that, ants don't usually cause any problems on plants, they're usually looking for honeydew, which is secreted from aphids, so check your plants over for aphids, if you find any, depending on the amount, you can either wash them off with a hosepipe, or use a commercially available insecticide, once the aphids have gone, the ants will disappear, ants don't like wet places so keep you pots and beds moist but not too wet, Derek.

Aphids and scale insect both produce honeydew - as Derek says, ants on plants are usually symptomatic of one or the other. Ants do like to make nests in raised beds because they prefer drier situations, which is usually how a raised bed is. If you know where an ants' nest is from the telltale mound later on, you can open it up with a spade and pour boiling water into it, so long as that doesn't mean scalding nearby plants or their roots.

With regard to pots, its important to decide whether there's a nest inside the pot or whether the ants are actually on the plants for the reasons mentioned above. Just soaking the pots won't actually get rid of an ant's nest completely, but there is a procedure you can carry out to deal with one in a pot. Since its not clear that you have nests i the pots, there's not much point in making an extensive explanation at this stage, so get back to this thread later if you believe they are nesting in your pots.

Thank you both very much for your advice and information. I will go on a nest hunt tomorrow and see if I can find it. I will also keep an eye out for Aphids and scale insects and encourage them to leave!

Remember to check backs of leaves, stems and new growth particularly when looking for aphid or scale insect.

Irrelevant to the question but interesting - a few days ago I took the lid off a fullish compost bin that hadn't been opened for a while and there was an ants nest on the surface - very very fine soil with lots of holes in it, and a general business going on...I will just let them get on with it as they are doing no harm there.