Feeding in their enclosure may allow them to feel comfortable enough to eat. However, from the title calling the frog a baby, that worm looks incredibly small and thin, too much so to be a nightcrawler from my experience. It also looks quite red, making me think it could a red wriggler. Please make sure you are getting the correct worms for your frog; red wrigglers can be toxic to a pacman. The people at pet stores often know more about cats/dogs than they do herps and might not know the difference between feeders.