I caught this critter in my room this evening and it's something we've never seen before. It clearly has a stinger, it's quite agitated, and it buzzes. It also has a heartbeat or something you can see through it's chest.
Western Washington State, USA.
Another pic...
This is a robber fly (Diptera: Asilidae); they are ambush predators on other small arthropods. They usually lay in wait on a twig, stem, or some other structure until a potential meal approaches; they then dart out, seize their victim with their strong legs and insert their mouthparts before returning to their perch to dine in leisure. This is a large family with thousands of species; see http://tinyurl.com/l8x3ho for a small sampling.
Wow, yes it sure is. Can't believe how common they are yet I've never seen one of them. I did some research on them and it looks like they don't sting, but only poke humans with their mouthparts if provoked. In my second picture though, it really did look like a stinger. I let him/her go in the backyard this morning.
