Just let him eat it butt first if he insists on it. It wont hurt them. Usually they will drop it like DV said and find the head. As for aspen, I use a paper plate to feed mine on but she is a beast and I can pick her up and move her on the plate while she is eating. But I would just put the little rat on the plate or if its a frozen or pre killed, just use forceps and zombie dance it. I recently switched my little girl over to weaned rats and I pre kill those and just dangle them infront of her and she goes crazy and grabs it in secs.