Other common names
Pigmy Rattlesnake, Pygmy Rattlesnake
Most adult dusky pygmy rattlesnakes are about 12-24 inches (30-61 cm) in total length. This is a very small snake, but it is thick for its size. The body color varies from light to dark gray, and a lengthwise row of black or charcoal blotches disrupts a reddish-brown stripe running down the middle of the back. The tail is slender and ends in a tiny rattle. The head is distinct from the neck and has a black diagonal line just behind the eye. The coloration of juveniles is the same as described for adults, except the tail tip of juveniles is bright sulfur-yellow in color.
Range in Florida
Dusky pygmy rattlesnakes are found throughout Florida and in every county. They are not known to occur in the Florida Keys, but they have been found on some barrier islands (e.g., St. Vincent in Franklin county).
Assessment of risk to people and pets
VENOMOUS The pygmy rattlesnake bites are painful but generally not considered life-threatening to people or pets. However, bites can be more serious to children and small pets. As with all venomous snakebites, the victim should seek immediate medical care from a physician or hospital experienced in treating snakebites. Pygmy rattlesnakes are not aggressive and avoid direct contact with people and pets. Most bites occur when the snakes are intentionally molested or accidentally stepped on.
Comparison with other species
Non-venomous hognose snakes (species in the genus Heterodon) are often confused with the dusky pygmy rattlesnakes because they have similar patterns and live in similar habitats. However, hognose snakes have both an upturned nose (rostral scale) and round pupils, and they lack both facial pits and rattles.
North American racer (Coluber constrictor) Juvenile black racers are small and have a pattern of reddish-brown saddles down their backs on a gray background. Furthermore, they may strike and vibrate the tip of their tail to produce a buzzing sound in leaf litter. As such, these non-venomous snakes are commonly confused with pygmy rattlesnakes. However, juvenile black racers are pencil thin, have tiny heads with large eyes and round pupils, and lack rattles on their tails.
Most adult dusky pygmy rattlesnakes are about 12-24 inches (30-61 cm) in total length, with a record length recorded of 31 inches (79 cm). This is a very small snake, but it is thick for its size. The body color varies from light to dark gray, and a lengthwise row of black or charcoal blotches disrupts a reddish-brown stripe running down the middle of the back. Dark spots occur on the sides and line up with the dorsal blotches. The tail is slender and ends in a tiny rattle. The belly is heavily mottled with black and white. The dorsal scales of the body are keeled (each scale has a prominent raised ridge). The head is distinct from the neck and has a black diagonal line just behind the eye. The pupil is vertically elliptical (cat-like), and there is a deep facial pit organ located between the nostril and the eye. The top of the head between the eyes is covered with nine large plate-like scales. The coloration of juveniles is the same as described for adults, except the tail tip of juveniles is bright sulfur-yellow in color. The tip of the tail of newborns ends in a “button”, which is the first segment of the future rattle.
Pygmy rattlesnakes are commonly found in habitats including lowland pine flatwoods, hydric hammocks, prairies, around lakes and ponds, and along the borders of many freshwater marshes and cypress swamps. Possibly the habitat in which dusky pygmy rattlesnakes are most frequently encountered, at least in southern Florida, is along the banks of canals running through marshes and prairies. This species can be locally very abundant, and it is often found in suburban neighborhoods where development encroaches into favorable habitats.
Pygmy rattlesnakes rely heavily on superb camouflage to avoid detection. When frightened, these snakes often remain motionless and expand their ribs so their bodies appear flattened against the ground. However, if provoked they may attempt to escape or they may remain coiled and shake their tails, producing a faint buzzing sound that could easily be mistaken for a buzzing insect. If further provoked, they may bob their heads and strike. However, these snakes are not aggressive, and striking is only used in defense.
Pygmy rattlesnakes feed on a wide range of small prey including centipedes and other arthropods, frogs, snakes, lizards, and small mammals. These snakes may actively pursue prey by following their scent trails, but more typically these snakes sit and wait to ambush prey. Juveniles have a bright sulfur-yellow tail tip, which they raise and wiggle like a caterpillar to lure prey within striking range.
In Florida, females typically give birth to around 1-14 live young between July and August. Females remain with the young for several days, after which time they all disperse. Competing males engage in combat dances when trailing females during the breeding season.
The dusky pygmy rattlesnake is the smallest species of venomous snake in Florida.
Three subspecies are currently recognized. Of these three, only the dusky pygmy rattlesnake (Sistrurus miliarius barbouri) is found in Florida.
Pygmy rattlesnakes are beneficial to people because they prey on many rodent species that are considered pests. Nevertheless, many are unfortunately killed by people every year.
Alachua, Baker, Bay, Bradford, Brevard, Calhoun, Charlotte, Citrus, Clay, Collier, Columbia, DeSoto, Dixie, Duval, Escambia, Flagler, Franklin, Gadsden, Glades, Gulf, Hamilton, Hardee, Hendry, Hernando, Highlands, Hillsborough, Holmes, Indian River, Jackson, Jefferson, Lafayette, Lake, Lee, Leon, Levy, Liberty, Madison, Marion, Martin, Miami-Dade, Monroe, Nassau, Okaloosa, Okeechobee, Orange, Osceola, Palm Beach, Pasco, Pinellas, Polk, Putnam, Santa Rosa, Sarasota, Seminole, St. Johns, St. Lucie, Sumter, Taylor, Volusia, Wakulla, Walton, Washington
If you have a new or interesting observation for this species, please email the herpetology staff at the Florida Museum.
Blaney, R.M. 1971. An annotated checklist and bibliographic analysis of the insular herpetofauna of the Apalachicola region, Florida. Herpetologica 27(4): 406-430.
Ernst, C.H. and E.M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Institution Press, Washington, DC. 668 pp.
Krysko, K.L., K.M. Enge, and P.E. Moler. Amphibians and Reptiles of Florida. 2019. University of Florida Press, Gainesville, Florida. 706 pp.
Powell, R., R. Conant, and J.T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America. Fourth edition. Houghton Mifflin Harcourt Publishing Company, Boston and New York. xiv + 494 pp.
Share your observations
You can help scientists better understand the biology and distribution of this species by sharing your observations. Send photos or videos of interesting observations, along with associated information, by emailing the herpetology staff at the Florida Museum for documentation in the Museum’s Herpetology Master Database. You can also post your observations on iNaturalist.
Additional helpful information
Do you have snakes around your house? Learn how to safely co-exist with snakes.
Still have questions about snakes or identifications? Feel free to email the herpetology staff at the Florida Museum with your questions or feedback on this profile.
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