TICKS

TICKS

Ticks are tiny blood-sucking anthropods that resemble small spiders or mites. The species Ixodes ricinus, often known as the deer or sheep tick, is the one most often found on humans. The larvae only have six legs, but the nymphs and adults have eight legs.

Ticks cannot fly or jump but climb on an animal when it passes by. They may be present on their host animal, including humans, for several hours before feeding. To feed, they bite into the animal to attach themselves to the skin. They then feed on blood from the host and after five to seven days they drop off when full. Because the tick's saliva carries a natural anaesthetic, you may not notice being bitten.

Before they have fed, ticks are so small they can be mistaken for a speck of dirt or a freckle. They can be as small as a poppy seed.

After feeding, adult ticks can be the size of a small pea and become lighter in colour.

RANGE AND HABITAT

Tick species are widely distributed around the world, but they tend to flourish more in countries with warm, humid climates, because they require a certain amount of moisture in the air to undergo metamorphosis, and because low temperatures inhibit their development from egg to larva. Ticks of domestic animals are especially common and varied in tropical countries, where they cause considerable harm to livestock by transmission of many species of pathogens and also causing direct parasitic damage.

For an ecosystem to support ticks, it must satisfy two requirements: the population density of host species in the area must be high enough, and humidity must be high enough for ticks to remain hydrated. Due to their role in transmitting Lyme disease, ixodid ticks, particularly I. scapularis, have been studied using geographic information systems (GIS), to develop predictive models for ideal tick habitats. According to these studies, certain features of a given microclimate such as sandy soil, hardwood trees, rivers, and the presence of deer were determined to be good predictors of dense tick 

LIFE CYCLE