Veterinary ethology distinguishes between predator and prey signaling strategies. A prey species (e.g., a rabbit) that overtly displays pain becomes a target for predation. Consequently, their ethogram of pain is subtle: reduced grooming, decreased locomotion, or changes in facial expression (e.g., the Rabbit Grimace Scale). A predator species (e.g., a dog) may display more overt vocalization but still retains a strong instinct to hide weakness.