build a sand box and mix dried mealworms and treats in the sand so they have to scratch around for them
I don't know how much your dried mealworms cost you but they are too cost prohibitive in my budget to lose in a sandbox. They break apart easily and half the pieces scatter and waste. So we just feed the mealworms by hand over the patio cement so the broken and dropped pieces can be found easily by the eagle-eyed chickens. Other treats and maybe wild bird seed in the sand would be good as they aren't as expensive to lose as dried mealworms.