[Terry]

Have just come across two very big ants nest were I am going to plant my sring cabbage should I do anything about them

[pushrod]

IMO yes. Boiling water or disturb them as much as possible so they go away - although they might come back!

[willowman]

I have a sneaking respect for ants, because of their social way of living and their survival instinct. They will be around long after we humans have blown ourselves to bits. Have you ever watched ants scurrying around if you kill one of their colleagues? Makes me think they actually have telepathic powers.
Having said that, I also loath them with a vengence. I think they are a right pain in the garden and should all be nuked.
That will upset some people who say that ants actually help the garden by churning up the soil. Sorry, but I can do that without their help. They infiltrate everywhere, sheds, houses, outbuildings, and cause a lot of misery.
Boil them, fire bomb them, just get rid of the lot of them.
Oops, sorry, rant over.

[Plottered]

When we had the little S**ts in the house we used some traps called "ant stop" and they were gone in a couple of days. they go in the trap which has some poison inside and take the poison back to the nest which then destroys the lot (hopefully).