Pinheads will eventually grow into large crickets. Depending on the dart they can be fed for a few weeks until they get to big. Keeping the crickets cooler than say 72F will slow down their growth cycle. If you have other frogs or pets to feed off any leftover crickets that would be great. Alternating pinheads, fruit fly, and springtails is great. Also Tropical isopods like Dwarf White Isopods are prolific and can be cultured inside and outside of the tank. We dump isopods into feeder bowls and those that escape seed the tank and act ask tank cleaners eating detritus until they are gobbled up of course.