Are you in an area that you can dig up some earth worms...your yard...the neighbor's yard (just kidding)...You must make sure the area you choose to dig has not been fertilized or sprayed for sometime...if you've got such a place, there is no more nuriousing food than earth worms!!! Obviously they should be kinda small (or chop them up), rinse them very well, and let your betta snack on 1 or 2 pieces of a nice tastey worm. They'll love you for it!! Make sure you're careful about your dig and rinsing. See if that doesn't spice up your betta keeping a little?