Life needs to stop finding a way (red ant edition)

I am so sick of these nasty little shits. I manage to get them off the lawn were the kids play, and apparently they've decided to start taking over the ecological niche of termites. They are moving into segments of an outdoor wooden playhouse, and burrowing holes into parts of the wood. I see their nasty little asses going in and out and leaving piles of sawdust.

Since mound destroyer or topical treatment wouldn't work for these vertically dwelling ants, has anyone else experienced this, and what kind of ant poison would work to spray into the joints of the wood. I am all for eco-friendly too, but not in this case.