First of all, it looks like a snake because of the elongated prothorax. Both adults and immatures eat aphids, mites, etc. Because they are predators as both adults and larvae, they have been considered as biocontrol agents.
The female lays eggs in bark or rotten wood. After the eggs hatch, there are 10-11 instars. Pupation takes place in a cell. But the pupa, which can move, sometimes leaves the cell for a second location before the adult emerges.
They commonly live in coniferous forests in the Western US, and around the globe. But this one was in a suburban home. Maybe I brought it inside inadvertently. There are some conifers around there. There are also conifers at the Bot Garden. But I would not call those places coniferous forest.
Thanks to wikipedia for the info.