Female killer whales reach sexual maturity when they grow to about 15-18 feet (4.6 m-5.4 m) long, depending on geographic region. The gestation period for killer whales varies from 15-18 months. Birth may take place in any month--there is no distinct calving season. Calves are nursed for at least 1 year, and may be weaned between 1-2 years old. The birth rate for killer whales is not well understood, but, in some populations, is estimated as every 5 years for an average period of 25 years. Killer whales are highly social animals that occur primarily in relatively stable social groups that often range in size from 2 to 15 animals.
Other symptoms that alert you to a case of head lice include a ticklish feeling on your head, especially at night. The head louse is a nocturnal creature and is more active in the dark than during the light of day.
What are head lice? The head louse, or Pediculus humanus capitis, is a parasitic insect that can be found on the head, eyebrows, and eyelashes of people. Head lice feed on human blood several times a day and live close to the human scalp. Head lice are not known to spread disease.