I was sharing the office this morning with a couple of these little spiders. By little, I mean far less than a centimetre in diameter, legs included.
They're called Zebra Jumping Spiders (Salticus scenicus), and to an arachnophile they're very entertaining.
The Salticids (jumping spiders) don't make webs but instead actively leap at their prey. Because of this they need very good eyesight. Yes, there really are spiders with good eyesight.
Jumping spiders are quite aware of their environment and will turn with characteristic jerky motions to follow every movement made near them. It makes it a bit hard to take photos of them with an autofocus camera, since the spiders are constantly coming closer to check out what you're doing.
Zebra Jumpers are found in both North America and Europe. They get their common name from the black and white stripes found on their abdomens.
These little spiders are harmless to humans and are actually kind of fun to watch as they leap around their habitats. And sometimes their habitat can be the desk of an easily distracted naturalist, apparently. Thanks, boys. I enjoyed the visit.