Many people raise and own hermit crabs--a type of crustacean that lives in seashells--for money or as pets. A female hermit crab doesn't give birth to a single "baby" hermit crab but produces many eggs, which she attaches to her soft abdomen. The eggs take approximately one month to mature, and then the female hermit crab releases them into salt water so the baby hermit crabs, or larvae, can hatch. The color of the eggs shows how much time is left before the eggs are mature, so just check the egg color to know when a hermit crab is going to have her babies.
Pick up your female hermit crab carefully by the shell, supporting the hermit crab/shell with both hands.
Check the female hermit crab's abdomen for eggs.
Look at the egg color. If the eggs have a red brick color, wait approximately four weeks for the unborn baby hermit crabs to mature. If the eggs have a dark gray color, wait no longer--the baby hermit crabs can hatch as soon as the eggs encounter salt water. If the eggs haven't turned gray yet, wait two weeks or more for the hatching.