A dog’s tale: isolated, contaminated, inbred, yet surviving While worms persist unseen in Chernobyl’s soil, more conspicuous survivors roam its streets and forests: free-ranging dogs.

Hammerhead worms are believed to have been introduced in the U.S. in 1891 through infested plants and soil.

Hammerhead worms are able to reproduce asexually, and do so in a hydralike manner. Experts warn not to attempt to cut the worm in half if you see one, as the two pieces of the worm will then ...