My Venezuelan Suntiger tarantula (Psalmopoeus irminia) does the "happy dance" after subduing it's prey, not because it's happy, but because it is laying a bit of web down. No one knows exactly why they do this, however i have read theories that the dance may be done to lay web down so they can listen for potential threats while they're eating. Tarantulas are vulnerable when eating, as their fangs are occupied by their prey. The web may allow them to better sense vibrations around them.

The Venezuelan Suntiger is a beautiful tarantula from Venezuela. It sports beautiful orange colorations on a dark gray/black base. They are lightening fast, quite skittish, and they do not have urticating hairs (which is unusual for new world tarantulas). They make for good pets because they are reluctant to bite, they're stunningly beautiful, easy to take care of, and ferocious eaters.