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.
They cannot fly or jump, but they can crawl. 24 hours after mating, female head lice lays her eggs (nits) on the hair shaft about 1/4-inch away from the scalp, although they can be found anywhere on the scalp. Lice can live up to a month and can lay up to 10 eggs a day. An egg takes 7-10 days to hatch. A nymph is a baby louse. A nymph takes 7-10 days to mature into an adult louse. Only adults can lay eggs. The dark brown eggs are the newly laid eggs. Nymphs are transparent, except for a dark center.