It depends on the species but over all turtles shouldn't eat dairy or milk products, rocks (i know it sounds crazy but some turtles will eat rocks and be okay but others will have an impaction and die), raw or cooked shrimp (unless sold as a turtle food in a pet shop), and potato chips and human food in general.
You CAN feed turtles hard boiled eggs (just keep them from gorging them selves (females and babies love them sooo much that they often stuff them selves to the puking point, males just think their okay), tiny amounts of raw ground beef, cooked chicken, and soggy dog food, earth or blood worms, crickets, snails, tadpoles, and several kinds of aquatic plants. Turtle pellets are a very good option also.
a turtle should eat as much seafood as a turtle can but not so much seafood that the turtle is sick
If a turtle doesn't eat for several days, you should take it to the vet. When an animal doesn't eat it could be the sign of all kinds of different things. Remember, a turtle doesn't have to eat every day, and they don't have to eat a lot. A large turtle can live on one banana a week.
you should kill it because it isn't going to eat
Take your turtle to a qualified reptile or exotic vet.
A guinea pig cannot and will not eat a turtle.
A turtle that won't eat is probably sick. It could be as simple as insufficient warmth. Consult an expert at the pet store about sort of temperature a turtle aquarium should be. You may also need to see a vet.
you can eat an african sea turtle
An alligator could eat a turtle in its shell, and a shark could eat a sea turtle in its shell.
Maybe it's hungry. When my turtle attempted to eat rocks, I fed it food, and it stopped. You must always feed your turtle to their fullest. If your turtle actually ate the rocks, you should see the vet immediately to check its stomach because no animal or person should eat rocks because it's inedible and very harmful to health. Hope this helped!
If you feed it to it when its really young and teach it to it should but if it gets a bit too old it will be difficult but it is possible.
Try it. Get a turtle and a round small tomato and see if the turtle can eat the round tomato.
the dear eat the white turtle head