ants...

last year a colony of ants set up home under one of my terra cotta pots in the patio. It looked like the "abode" was in between two slabs of concrete.

This year it seems to have taken over the pot itself and now there are signs of tunnels all around the pot, as well as the space between the concrete slabs.

Is this something that I should be concerned about, or should I just let nature do its thing and live in harmony with them? I do see the occasional ant in my place but aside from that they haven't been a bother. I really would rather not have to do anything, but I am getting concerned about the plant inside the pot (california lilac).

Speaking as a bee keeper, I'd choose to just think of it as an ant farm. I like helping outdoor insects find habitat. Since they are building their home in the sand around the concrete, they are not carpenter ants which could actually hurt your house. If you moved the pot, it would be interesting to see which 'home' they went with- the pot or the concrete.

If you put your pots up on bricks, the ants are less likely to take up residence in the pots, although they might try to under the brick. They like it dark and damp, like under and in a pot that sits directly on the patio or deck. Raising the pot on bricks keeps the area below the pot dry and airy and light, which ants don't like.

Sounds like they might be pavement ants, who like to like in...concrete, of course. We've had them around our house's foundation. They're pretty harmless as long as they're not establishing themselves inside, and treating them outside always seemed kind of futile to me---I mean, we have lots of concrete around the house for them to love. :p They won't harm your plants.

I have some that live in my concrete cracks too. I see them once in a blue moon - I'll come home and my porch will be CRAWLING with ants. And then by the morning, they're hiding again. Weird.

sounds like they're part of the patio ecology then :) I'll leave them be.

Just don't bring your plants (and ants) inside.