Thus a pair of brown rats can produce as many as 2,000 descendants in a year if left to breed unchecked. (A rat matures sexually at age three to four months.) An average rat's life span is two to three years.5 A rat can tread water for three days and survive being flushed down the toilet.hus a pair of brown rats can produce as many as 2,000 descendants in a year if left to breed unchecked. (A rat matures sexually at age three to four months.) An average rat's life span is two to three years.
Late lice. The common head louse, Pediculus humanus capitis, may take as long as 14 days to hatch. Gilles San Martin/Wikimedia Commons. Hereâs some lousy news for parents of itchy-headed kids: Lice eggs can take 2 weeks to hatch in human hair, making standard 7-day delousing treatments ineffective in some cases.
Certain conditions affect the length of time that lice eggs can survive without a host. For example, lice eggs cannot hatch in temperatures lower than that of the average body temperature, which is 98.6 degrees Fahrenheit. However, adult lice and nymphs are not affect by temperature changes. Lice eggs take between eight to nine days to hatch. Once born, it takes about nine to 12 days for a nymph to mature and become an adult lice. Without treatment or removal from an infected area, the total lifespan of adult lice is 30 days. Adult female lice can lay up to six eggs per day. Lice are a kind of parasitic insect that rely on consuming small amounts of blood absorbed through the scalp several times a day to survive. Lice are most commonly found at the base of the scalp.