Why shouldn't you paint a hermit crabs shell?

Painting a hermit crab's shell can harm the animal by disrupting its ability to breathe and causing stress. The paint can contain toxic chemicals that may be harmful if ingested or absorbed through their skin. Additionally, altering their shell can interfere with their natural behavior and instincts, which could lead to health issues or even death. It's best to allow hermit crabs to choose their own shells naturally.