Try feeding other things. Maybe frozen blood worms or flakes. My gardneri eat pretty much anything I give them... I feed them live bugs that I find in my house even.
+1 as far as nothos go anyway.I have never seen my killis eat anything not moving, so I would keep up with anything alive, and my nothos also only eat about a worm a day at the most unless they've been breeding recently. So I would just keep up with offering a few worms a day or give brine shrimp a try if you have access to them. But killis are notorious for only eating live foods.