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.
Gestation time for head lice is 10 days from the point that a female lays the eggs and the nits hatch.An adult can live for up to 30 days on its host. If bedding and other items are not properly treated, eggs can hatch and a nit can reinfect a host. add a comment.nswer by mcmario2007 (786). The gestation time for head lice is approximately ten days and the best way to get rid of the lice is to use a proper shampoo meant to exterminate head lice. add a comment.