i Don't know if there is a exact answer right now i feed my sub adult about 1 nightcrawler a day sometimes two if she is extra hungry but i think 3-4 isnt bad i know you could feed more if he is a adult maybe try seeing if he wants more i generally try to feeding tell he or she doesnt want anymore and then wait 3-5 days. i think rule of thumb is try feeding as many as the frog wants whiten a 15 min period. Someone will come correct me if i am wrong.