Some kind of Ichneumon parasitoid species I think, but I haven't ID'd them yet. I try to keep my household IPM limited to biocontrols and the most harmless chemicals. My houseplants are full of soil macrofauna, assassin bugs, parasitoid wasps, non-venomous spiders, and other beneficial insects that control the species I don't want.
These wasps are totally harmless to humans and animals, the size of a small carpenter ant. The "stinger" is an ovipositor that they use to lay eggs in pest insects, and spiders as well which keeps their population in check. I've noticed maybe 30-50 overwintering inside, just sitting around beggin' for an eggin'.
Turn your home into an ecosystem. Fill it with wasps.
Oh, so that's what those are! Thanks for telling me about their behaviour. I've been seeing these in my house as well. Cool that they live in both hemispheres.