They are excellent swimmers and can easily capture aquatic turtles. They hunt from dusk to dawn. Weasels, mink and ferrets are adept at squeezing through incredibly small openings and pose a significant danger in areas where they are found. Dogs should never be allowed unsupervised access to turtles or tortoises. Dog bites are among the most common of all tortoise injuries.
Coyotes pose the same danger as well and hunt at night.
Feral housecats pose a threat to hatchlings, bobcats pose a threat to all tortoises and turtles. Fireants kill hatchling tortoises and destroy eggs as well. Fireants must not be allowed in the enclosure. Yellow Jackets and other ground wasps will sting any turtle that ventures too close to their nest. Unfortunately in any but the largest pens a turtle or tortoise can not avoid doing so.