Lauren Sommer

They're wiggly and slimy and live inside the flesh of other animals. Now, scientists are making a new case for why they should be saved.

Parasites play crucial roles in ecosystems around the world, making up around 40% of animal species. As wildlife faces the growing threats of climate change and habitat loss, scientists warn that parasites are equally vulnerable.

That's why a team of scientists has released a "global parasite conservation plan."

When Kirsten Delegard's grandparents bought their first house in south Minneapolis in 1941, they signed the property's deed, as is standard for any homebuyer.

But the deed came with this line: "No person or persons other than of the Caucasian race shall be permitted to occupy said premises or any part thereof."