adaptive behavioral response induced by higher stress levels (and thus, elevated corticosteroids). However, exposure to fire ants did not increase the percentage of lizards that demonstrates escape behavior. Instead, those that had priorly shown escape behavior were more likely to show escape behavior earlier and more strongly. In other words, this behavior is not learned, but can be shaped if already present. The number of twitches performed by a lizard is also not affected by previous exposure. Juveniles, which are younger and smaller, flee more rapidly than adults in any encounter. Furthermore, within the past 70 years, according to a study published in 2009, eastern fence lizards in certain regions have adapted to have longer legs and new behaviors to escape the red imported fire ant, which can kill the lizard in under a minute. Given the incubation period of the eggs, one study suggests that 61% of nests may be at risk of predation by these invasive fire ants. Nest choice and distance to the nearest fire ant mound did not significantly impact predation; thus, because there is little that eastern fence lizards can do to resist such predation on their eggs, there is conservation efforts toward stopping invasive species such as this fire ant. Gallery References PAULY, G. B. (2012). Evidence for Freeze Tolerance in the Eastern Fence Lizard (Sceloporus Undulatus). Southwestern Naturalist, 57(4), 472–473. https://doi.org/10.1894/0038-4909-57.4.472 External links Pictures and resource information on the eastern fence lizards Care sheet for pet owners of the eastern fence lizard Further reading Behler, John L.; King, F. Wayne (1979). The Audubon Society Field Guide to North American Reptiles and Amphibians. New York: Alfred A. Knopf. 743 pp., 657 color plates. . (Sceloporus undulatus, pp. 529–530 + Plate 375). Powell R, Conant R, Collins JT (2016). Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America, Fourth Edition. Boston and New York: Houghton Mifflin Harcourt. xiv + 494 pp., 47 Plates, 207 Figures. . (Sceloporus undulatus, p. 298 + Plate 27 + Map on p. 294). Smith, Hobart M.; Brodie, Edmund D., Jr. (1982). Reptiles of North America: A Guide to Field Identification. New York: Golden Press. 240 pp. (paperback), (hardcover). (Sceloporus undulatus, pp. 122–123). Zim HS, Smith HM (1956). Reptiles and Amphibians: A Guide to Familiar American Species: A Golden Nature Guide. New York: Simon and Schuster. 160 pp. (Sceloporus undulatus, pp. 57, 155). Sceloporus Reptiles of Mexico