Tick Lifecycles

Key points

  • Most ticks go through four life stages: egg, six-legged larva, eight-legged nymph, and adult. After hatching from the eggs, ticks must eat blood at every stage to survive.
  • Ticks usually acquire pathogens early in their life (larval or nymphal stages) when they feed on animals. They transmit those pathogens to other animals or to people later in their life (nymphal or adult stages).
Photo of all life stages of blacklegged ticks on a dime.

Hosts

Ticks can feed on mammals, birds, reptiles, and amphibians. Most ticks prefer to have a different host animal at each stage of their life. Ticks that require this many hosts can take up to 3 years to complete their full life cycle, and most will die because they don’t find a host for their next feeding. Some tick species, like the brown dog tick, prefer to feed on the same host during all life stages.

Keep reading‎

More information about how ticks find their hosts.

Lifecycles

Ixodes scapularis

The lifecycle of Ixodes scapularis ticks generally lasts two years. During this time, they go through four life stages: egg, larva, nymph, and adult. After the eggs hatch, the ticks must have a blood meal at every stage to survive. Blacklegged ticks can feed from mammals, birds, reptiles, and amphibians. The ticks need a new host at each stage of their life.

Ixodes scapularis typically lays eggs in the spring. These hatch into larva in the summer. The following spring, nymphs feed and then molt into adults later in the fall. Adult females will seek a blood meal and lay eggs the following spring, completing the lifecycle.
Blacklegged tick (Ixodes scapularis) lifecycle.

Ixodes pacificus

The lifecycle of Ixodes pacificus ticks generally lasts three years. During this time, they go through four life stages: egg, larva, nymph, and adult. After the eggs hatch, the ticks must have a blood meal at every stage to survive. Blacklegged ticks can feed from mammals, birds, reptiles, and amphibians. The ticks need a new host at each stage of their life.

Ixodes pacificus typically lays eggs in the spring. These hatch into larva the following spring. During the summer, larvae feed and then molt into nymphs the following spring. During the summer, nymphs feed and then molt into adults over the winter. Adult females will seek a winter or spring blood meal before laying eggs in spring, completing the lifecycle.
Western blacklegged tick (Ixodes pacificus) lifecycle.

Rhipicephalus sanguineus

Rhipicephalus sanguineus, brown dog ticks, spread the bacteria that causes Rocky Mountain spotted fever in some parts of the southwestern United States and Mexico.

Image shows Rhipicephalus sanguineus at different life stages feeding on three canine hosts. The diagram shows potential pathways for Rickettsia rickettsii to transmit to a human host.
This diagram shows the typical lifecycle of brown dog ticks (Rhipicephalus sanguineus).