Just make sure they are actual night crawlers and not red wigglers or composting worms as many frogs seem to detest those. I was feeding Canadian night crawlers to my White's tree frogs, and they seemed to love them for a while, but I couldn't find any small enough-- the full worm seemed to give them too much trouble, and cutting the slimy things up into bite sided bits (that they may or may not take) caused me too much trouble! Looking for a source of smaller sized Canadian night crawlers now. I was keeping mine in the fridge. Apparently to raise them they have to have way cooler temps even than what it is in or outside our apartment; they're best kept around 55F or something like that(?).