The Ant Hill Mob

I decided to stop putting things in my main compost bin so that it can all turn to soil for pots and replacing some patches of old soil. In the mean time, I've been putting waste into an old plastic box in the garden with a lid. I put a bit of soil at the bottom and started filling it a few weeks ago.
I just opened the lid to throw more stuff in, and suddenly there's a porpus mound of soil in the middle of the box, about 6" across and nearly as high. Ants are swarming all over it, so I assume they've decided to build a colony in my box.
Is there any potential problem with this? If I keep throwing stuff into the box, it'll destroy the colony, and I'm happy to leave them alone if they're good to have around a garden. Will they go away at the end of the year or something?
Posts
if you tip it on the ground the blackbirds will sort it out, and then you can just shovel it back in the box.
They like dry places for their nests so, once you've got them picked off, put it all back and keep the compost heap moist. It'll help break it down faster too.
"We don't stop playing because we grow old; we grow old because we stop playing." - George Bernard Shaw
Ants not generally good. Can completely undermine a planted area, so not welcome in my garden, plus they 'farm' aphids for the honeydew they excrete, so whilst not directly harmful to plants, can still be pest. They don't like water, so give them a good soaking and they'll go away.