Bathysquilla wetherelli was a mantis shrimp, an active predatory crustacean rather than a true shrimp. Mantis shrimps use specialised front limbs to seize or strike prey, and this species would probably have hunted small fish, worms and other crustaceans around the seabed.

It represents one of the more specialised hunters in the London Clay crustacean fauna. Living mantis shrimps are alert, fast and visually sophisticated animals, so fossils such as B. wetherelli show that similarly specialised predatory body plans were already established in the Eocene seas.