Flea and Lice Facts



  • Fleas and lice are small wingless insects that live on birds and mammals, including humans. Dogs, cats and rats are especially prone to fleas.
  • Fleas and sucking lice suck their host’s blood.
  • Chewing lice chew on their host’s skin and hair or feathers. Chewing lice do not live on humans.
  • The human head louse has a body length of 2-3mm. Once its crab-like legs and hooked claws cling to its victim’s hair or skin, it is harder to shift than a limpet on a seaside rock.
  • Fleas and lice are often too small to see easily. But adult fleas grow to over 2 mm long.
  • A flea can jump 30 cm in the air equivalent of–the a human leaping 200 m in the air.
  • The fleas in flea circuses perform tricks such as jumping through hoops and pulling wagons.
  • Fleas spread by jumping from one animal to another, to suck their blood.
  • When fleas lay their eggs, they hatch as larvae and crawl off into the host’s bedding, where they spin cocoons and emerge as adults 2 weeks later.
  • Head lice gum their nits (eggs) to hair and spread from head to head through sharing of combs and hats.
  • Fleas jump with a force of 140 g – over 20 times that required to launch a space rocket.