I'll "third" the "leave them over-night" response. And if I happen to need to feed live pinkies to a problem feeder, I leave it for as long as the pinky stays alive, which can be 2-3 days. Some of the problem feeders are intimidated by a strong and active pinky, but will eat them when they become weak. I currently have 2 hatchlings now that won't eat their live pinky until the second day/night...but I'm really glad that they're eating!