where did you get these kittens from? I have bengals and can tell you they should stay with the mother until at least eight to ten weeks old. But even at six weeks they should be eating solid food on their own. Have you tried wet food? something with a lot of gravy so they can lick it up. You have to be careful where you get them from, with bengals being a popular cat there are many backyard and kitty mill breeders. Contack the one you got them from and see if they will take them back for a couple more weeks. they still need their mom. Your other option is if the breeder didn't supply you with a current health certificate if they don't co operate with you you can get them in big trouble. Push the incident, these so called breeders should be punished for this the health certificate can be no longer than 14 days before you get the kitten and NO vet will issue a kitten at four weeks old which is when the health certificate would be given. check it out, stop these breeders before selling more innocent sickly kittens