As I was biking up Mount Diablo the other day, I came across an animal I'd been keeping an eye out for: a male tarantula in wanderlust. They're easiest to spot as they cross the road, and this one was quite determined to get to the other side.
In the fall the male tarantulas set off in search of females to mate with. If she doesn't eat him (which she'll only do if she's famished) he'll keep looking for partners until the cold weather, or a hungry lover, gets him. Females, on the other hand, can live up to twenty years.
I've always liked spiders but this one was wary of me and wouldn't stay on my hand. That's OK :-)
This article has more information about these fascinating creatures.