Bettas are smart, as far as fish go, and certainly they're pigs. While we owners may like the idea that the fish is swimming up to us because they're just overjoyed to see us, in reality, they want to be fed.
That's not a bad thing though, as their extreme fondness for food can make for easy teaching. Probably the easiest trick to teach a Betta is to jump for their food.
- Feed only from your fingers until the fish can be hand fed without hesitation.
- Feed only from the fingers, keeping the food JUST under the water level.
- Slowly raise the food so that the fish has to jump a bit out of the water to grab it from your fingers.
- Ta-da, you have a fish that will jump for his food.
Frozen Bloodworms work well for Betta training, as they're long enough to easily hold. (And Bettas LOVE them.)
Be sure that you feed the fish in the middle of the tank so that they don't jump out.
Also, be sure that you don't overfeed the fish during training. Overfeeding can easily lead to swim bladder disorders.
On another note, I had a foster cat once who developed what could only be described as a relationship with one of my Bettas. She'd sit on a stool at one end of the aquarium, and the Betta would swim immediately to her, wiggle, and swim back and forth "flirting" with her as she batted the glass.
Certainly, both can and fish seemed to be in on the game. Pretty smart for a fish I'd say. (And the cat never fed him!)