Francois Savigny / Breeding ball of Anacondas {Eunectes murinus} Venezuela - up to 10 males surround one female

Chris Mattison,Chris Mattison / Rubber Boa (Charina bottae) in defensive posture, raising tail to mimic head. California, USA, November.

Daniel Heuclin / Dumeril's Ground Boa (Acrantophis dumerili) against white background. Endemic to Madagascar.

John Cancalosi / Boa Constrictor (Boa constrictor) shedding skin from head. Guanacaste National Park, Costa Rican tropical rainforest.

John Cancalosi / Boa Constrictor (Boa constrictor) shedding skin from head. Guanacaste National Park, Costa Rican tropical rainforest.

Daniel Heuclin / Close up of skin of Rainbow boa (Epicrates cenchria cenchria) captive, from French Guiana

Pete Oxford / Amazon Tree Boa (Corallus hortulanus) in rainforest, Iwokrama Reserve, Guyana, digitally manipulated image

Alex Hyde / Madagascar tree boa {Sanzinia madagascariensis} tropical rainforest. Masoala Peninsula National Park, north east Madagascar.

Edwin Giesbers / Madagascar ground boa (Acrantophis madagascariensis) Berenty Reserve, Madagascar

Michael D. Kern / Red Tailed Boa {Boa constrictor constrictor} captive, from South America

Pete Oxford / Anaconda {Eunectes murinus) after ingesting Peccary prey, night, Amazon, Ecuador, South America

Michael D. Kern / Amazon tree boa snake {Corallus hortulanus} portrait with tongue extended, captive, South America