Michael & Patricia Fogden / Black-tailed Rattlesnake (Crotalus molossus) portrait, Chiricahua Mountains, Arizona

Tom Vezo / Black-tailed Rattlesnake (Crotalus molossus), Arizona

Barry Mansell / Velvety / Pallas' free-tailed bat (Molossus molossus) feeding on fruit, introduced from Cuba, Florida Keys, USA

John Cancalosi / Black-tailed Rattlesnake (Crotalus molossus) striking. Chiricahua Mountains, Arizona, USA.

Pete Oxford / Head of Pallas' mastiff bat (Molossus molossus) captive, Karanambu Lodge, Rupununi, Guyana

John Cancalosi / Black-tailed Rattlesnake (Crotalus molossus) "tasting" the air with its tongue, Chiricahua Mountains, Arizona, USA

Michael D. Kern / Black-tailed rattlesnake (Crotalus molossus) coiled with tongue exposed and ready to strike, rattling tail, captive, from USA

Michael D. Kern / Black tailed rattlesnake (Crotalus molossus) captive, from SW USA and Mexico

Michael D. Kern / Black tailed rattlesnake (Crotalus molossus) captive, from SW USA and Mexico

John Cancalosi / Black-tailed Rattlesnake (Crotalus molossus) "Smelling" or "tasting" the air with its tongue. Chiricahua Mountains, Arizona, USA

John Cancalosi / Black-tailed Rattlesnake (Crotalus molossus) "Smelling" or "tasting" the air with its tongue. Chiricahua Mountains, Arizona, USA

John Cancalosi / Black-tailed Rattlesnake (Crotalus molossus) "Smelling" or "tasting" the air with its tongue. Chiricahua Mountains, Arizona, USA

Barry Mansell / Velvety Free-tailed / Miller's Mastiff Bat (Molossus pretiosus) roosting on a branch, Mexico

Barry Mansell / Black-tailed Rattlesnake (Crotalus molossus) scenting with forked tongue, Arizona, USA

Thomas Marent / Pallas's Mastiff Bat (Molossus molossus) portrait, Manu National Park, Peru

Michael D. Kern / Black tailed rattlesnake {Crotalus molossus} captive snake; occurs south western USA, Mexico, San Esteban and Tiburon Islands

John Cancalosi / Black-tailed Rattlesnake (Crotalus molossus) "Smelling" or "tasting" air with tongue, Arizona, USA

John Cancalosi / Black tailed rattlesnake coiled {Crotalus molossus} south east Arizona, USA

Heidi & Hans-Juergen Koch / Black-tailed Rattlesnake (Crotalus molossus) coiled in defensive posture, native to the southwestern United States

Michael & Patricia Fogden / Black-tailed Rattlesnake (Crotalus molossus) on rocks, Chiricahua Mountains, Arizona

Michael & Patricia Fogden / Black-tailed Rattlesnake (Crotalus molossus) on rocks, Chiricahua Mountains, Arizona

Michael & Patricia Fogden / Black-tailed Rattlesnake (Crotalus molossus) coiled near cactus, Chiricahua Mountains, Arizona

Michael & Patricia Fogden / Black-tailed Rattlesnake (Crotalus molossus) coiled on ground among leaf litter, Chiricahua Mountains, Arizona

LYNN M. STONE / Black tailed rattlesnake, Arizona, USA

John Cancalosi / Black Tailed Rattlesnake showing rattle. Arizona, USA

Tom Vezo / Black-tailed Rattlesnake (Crotalus molossus) in defensive posture, Arizona

Pete Oxford / Black-tailed Rattlesnake (Crotalus molossus) in defensive posture, native to Mexico and the United States

Robert Valentic / Black tailed rattlesnake {Crotalus molossus molossus} threat pose, captive