My juvvie nhandu chromatus (Brazilian red and white) tarantula throwing me a threat pose. I had been pouring some water into his dish and a drop splashed him. If you look close you can see his little glowing demon eyes!

This guy is my only t, out of 9, that ever gives me a threat pose. He's even struck at the Kritter Keeper lid I use to shield my hand when I reach in to pick up their water dishes (don't want to get mistaken for a cricket). I didn't know I was getting an aggressive t when I bought him, I just thought he was pretty (and cheap!). There's a video of him digging on youtube, here: http://www.youtube.com/watch?v=YvrN59SYfRY