I would feed about 6-8 1/4" crickets, once a day (make sure you are dusting with calcium). As far as one at a time or free range, it depends on the size of the cage. If he is in a fairly small cage, I would free range. If it is more of an adult enclosure I would Cup feed. Make sure you remove any crickets that are not eaten before night time, or check in the dark and remove them. This is just my opinion, take what you will from it, I am sure others may say diffrent.