Most invertebrates, such as insects, prefer warm temperatures and live in tropical areas. Insects adapted to survive frost include Nemoura arctica, a stonefly found in Alaska, which can withstand temperatures as cold as 5 degrees Fahrenheit. Nymphs of this species live in the water and can survive after spending more than two weeks encased in ice. Nemoura arctica can produce an antifreeze protein, when temperatures drop below 39 degrees Fahrenheit. Invertebrates also low their body temperatures to avoid ice crystal formation, by producing high levels of glycerol. The wolf spider Pardosa groenlandica only freezes at temperatures lower than 13 degrees Fahrenheit, while the larva of the moth Gynaephora groenlandica only freezes at 17.6 degrees Fahrenheit.
The wood frog (Rana sylvatica) is found from the Appalachians to Alaska. This species overwinters within the frost zone, in shallow burrows in the floor. The wood frog can survive temperatures as cold as 21 degrees Fahrenheit, as well as the freezing of up to 70 percent of its body fluids for about four weeks. High levels of glucose are produced under frost conditions, increasing its tolerance to freezing temperatures and protecting cells and organs against damage. The frog also accumulates urea to increase its resistance to frost.
Unlike many amphibians, hatchlings of painted turtles (Chrysemys picta) withstand exposure to frost and cold by avoiding freezing and lowering their body fluid temperatures. While most turtle species hatch during summer months, painted turtle hatchlings adapted to colder temperatures during their evolution. The European lizard Lacerta vivipara is another reptile species able to survive frost conditions.
Although several bird species migrate to warmer areas during winter, to avoid cold temperatures and frost, others have adapted to survive in both warm temperatures and frost conditions. The Australian tawny frogmouth (Podargus strigoides) and the North American common poorwill (Phalaenoptilus nuttallii) enter a state of torpor and reduce their body temperature to survive the frost during the winter months. Among mammals, hibernation is also common in some species, such as the Arctic ground squirrel, with periods of up to nine months, when body temperatures can reach 32 degrees Fahrenheit. A thick fur and extra layers of fat tissue also help to protect the body against frost in mammal species, such as the musk oxen.