a kitten question for anyone who knows the answer

She’s been driving me crazy all day with a new problem I don’t understand. After a certain period of bottle-feeding, she suddenly becomes extremely aggressive, puts her claws and teeth out, and tries to attack behind the bottle nipple to the larger volume of milk itself, which is of course physically impossible since there is no opening other than in the nipple.

All that I can think of is that she’s unsatisfied with the volume of the flow and wants more at once, but that is contradicted by the completely full mouth of milk I see her have when drinking the normal way.

If anyone has run into this problem while bottle-feeding kittens before and has found a solution, please let me know. She’s attacking my hand as part of the attack on the bottle each time, and those little claws already hurt.