Some animals have built-in armor. Some create their own! Octopus living on sand flats in Indonesia find and use coconut shells as an armored mobile home! Planning ahead, they will carry around 2 pieces and enclose themselves inside to ambush prey or hide from potential predators.
Sketch and fact contributed by Karli Chudeau
[Edited by Adrian Perez]
Source: Finn, J. K., Tregenza, T., & Norman, M. D. (2009). Defensive tool use in a coconut-carrying octopus. Current biology, 19(23), R1069-R1070.