Anatomy of a Tick 1column


  • Most people think ticks are a kind of insect.
  • They’re not!
  • They are technically classified as arthropods.
  • They are blood sucking arachnids closely related to spiders and scorpions.


  • The head consists of a sizeable serrated mouthpiece called a hypostome.
  • The adult tick has four sets of legs each of them covered in short, spiny hairs.
  • There is a shield on their back called a Scutum which is very tough.

Australia's paralysis tick
(Ixodes Holocyclus)

  • The scutum is smaller on the female and larger on the male.
  • The female's scutum is smaller so the sack can expand and have a good blood meal and house up to 3,000 tiny eggs.
  • Think of a tick as a little germ-filled balloon. Squeeze it too hard on its back end, and all the germs get pushed to the front end, which, is attached to you by the tick’s straw-like mouthpart.
  • In addition to their feeding behaviour and appearance, ticks are disease vectors. They can carrydiseases from one animal to another. In fact, ticks are the primary disease vector in domestic animals. Regarding human diseases, only one parasite spreads more illness and thats the mosquito. Ticks can spread a wide variety of disease-causing organisms, including bacteria, viruses and protozoa. How ticks spread their disease.


The Head of a Tick

Ticks use their mouthparts to pierce their hosts' skin and extract blood. These mouthparts can vary from species to species, but in general, from the outside to the inside, a tick's mouth includes:

  • Two palps, which move out of the way during feeding and don't pierce the host's skin
  • Two chelicerae, which cut through the host's skin
  • One barbed, needle like hypostome

  • The hypostome is a barbaric spear shaped blood sucking mouthpart.
  • With its curved barbs the hypostome is designed for the tick to stay for a while.
  • On either side of the hypostome are palps they are used to taste and find the best place to feed on a blood meal.

Ever Notice how Difficult it is to Brush a Tick Off?

  • They have a tiny but effective claw on the end of the leg and an adhesive pad.
  • These allow the tick to grasp onto its host. All you need to do is touch it.
  • The ticks, spiny hairs and claws also let the tick to grasp blades of grass, leaves, branches while questing.

How Ticks Find You

  • While some ticks can’t see you, they know exactly what is going on around them.
  • The Haller's organ is a minute cavity at the terminal segment of the first pair of a tick's legs


  • Each one is composed of a pit and a capsule, which contain sensory receptors called setae. These are bristle- or hair-like structures.


  • The Hallers organ can sense changes in the concentrations of Carbon Dioxide,
  • Changes of temperature like body heat and vibration.
  • They know when you're coming.

A Questing Tick

The Hard Tick is an Ambush Preditor

  • The Hard tick is an Ambush predator and have a behaviour known as Questing.
  • In this picture of a nymph tick on a leaf, its front legs are extended upwards sampling her environment.

  • Using the Hallers organ to sense changes in the concentrations of Carbon Dioxide, temperature, heat and vibration.
  • The tick searches, Quests for a warm blooded meal to move towards them.