I have a Motoro Pup & he is eating Nightcrawlers. He devours them as soon as they go in the tank! It's getting quite expensive so I tried to go outside after it rained & collect some worms for food. He won't touch them even after not feeding him for a few days? Then i went out & bought some more Nightcrawlers & BAM. He them in about 20 seconds? has anyone else ever encountered this?