nope, the nostrils only provide a way for them to breathe. sometimes the fishier and smellier they are the more the snakes can be attracted to it. some will eat before shed and some won't...and it depends on the snakes mood to, some will and then won't. I fed my snakes today, my huge melanistic eastern ate her big chunk of fish. I usually go in a couple hours after feeding to see whe ate and who didn't...the melanistic shed!