my male does this sometimes too. after i moved him into his T8 he went on a little hunger strike i think from the stress, and after he settled in and was showing interest in feeding he would show that same behavior. he comes out and stares at it, tongue flicking, then retreats. for the past 3 feedings i've left it in overnight and he's taken all three. i wonder if he's becoming a shy feeder? he hasn't shown a strike at prey since moving.