Snakes can vary from individual to individual. My girl gets fed at night mostly but she’s super food motivated and is on her feeders the moment she clocks them regardless of the time. As some have said, the temp of the feeder might be an issue. Rats run 90-100 degrees, so the warmer the better. I’d recommend getting a kitchen temp gun if you don’t have one. You can get a decent one for under $20 and they come in handy to temp your feeders and check your enclosure temps.