I recently bought a new thermometer for my aquarium. The Chinese Algae Eater (aka Spooky Fish) has been having a field day moving it from one side of the aquarium to the other. It's almost like the fish is sparring with the thermometer. Any ideas on why it's doing this?

And for your viewing entertainment, a video of spooky fish performing fish-Jiu-Jitsu on the thermometer.