Ichneumon Wasp

I will admit, my first reaction when this thing floated across B's and my ambling walk was "WTF IS THAT THING?!???" And I was a bit jittery while trying to get my phone closer for a photo.

Turns out it is a type of parasitic wasp in the large and diverse family of Ichneumonidae, with over 80,000 species (3,000 in North America). They lay eggs onto hosts (typically larvae of other insects) which grow off of the host, killing it when they (the wasp) pupate. The long tail helps drill through wood, etc. to reach the host and also serves as the egg-depositor. Though they apparently pose no threat to humans, they are just huge enough (at least this species) as to give you the heebee-jeebees, but just cool enough to keep you staring... and doing endless google image searches. :)