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.
Female Cichlid mouthbrooders typically incubate their eggs for a period of 21-32 days, with 28 days being more typical. It usually takes the eggs 14-21 days to hatch. If you end up with eggs that have not yet hatched (either accidentally or purposefully) it will be imperative to tumble them.emale Cichlid mouthbrooders typically incubate their eggs for a period of 21-32 days, with 28 days being more typical. It usually takes the eggs 14-21 days to hatch. If you end up with eggs that have not yet hatched (either accidentally or purposefully) it will be imperative to tumble them.