An eyedropper is too large. But because of their size, this is seldom successful. To prevent a problem, do not move or handle the mother or babies and she will normally take good care of them. They are nocturnal and would prefer to sleep during the day and play at night. They should be kept singly and need to be handled carefully and regularly or they can become nippy.
Gerbils are less nippy, but much faster if they get away.
Most enjoy gentle handling. Guinea pigs are somewhat larger and tend to enjoy handling their owners. They should be kept singly. All small children should be supervised while handling small animals, for the safety of the child and of the animal. These animals are all available on a regular basis and are easy to care for.