What does a tick in a house look like?

What does a tick in a house look like? - briefly

A house tick is a tiny, oval arachnid about 2–5 mm long, reddish‑brown to dark brown, with a smooth, flattened body and eight legs that become apparent when it expands while feeding. When engorged, it swells to a grape‑like size, turning pale and soft.

What does a tick in a house look like? - in detail

Ticks that wander indoors are small arachnids, typically ranging from 1 mm to 6 mm in length depending on species and developmental stage. Their bodies consist of two main sections: the anterior capitulum, which houses the mouthparts, and the posterior idiosoma, which contains the legs and internal organs. The capitulum appears as a tiny, forward‑projecting shield and may be darker than the rest of the body.

Size and shape

  • Larvae (seed ticks): approximately 0.5 mm, translucent or pale cream, with six legs.
  • Nymphs: 1–2 mm, reddish‑brown, eight legs, more robust than larvae.
  • Adult females: 3–5 mm when unfed, dark brown to black, oval, engorged females can swell to 10 mm.
  • Adult males: 2–3 mm, smaller than females, darker coloration, less rounded abdomen.

Coloration

  • Unfed stages exhibit a uniform brown or reddish hue.
  • Engorged females become markedly lighter, often appearing grayish‑white due to blood expansion.
  • Some species display a distinct dorsal pattern, such as a pale spot on the scutum of Ixodes ricinus.

Surface texture

  • The dorsal shield (scutum) is hard, glossy, and may have a slightly raised border.
  • The ventral side is softer, with visible segmentation in the legs.
  • Tick legs are relatively long compared to body width, ending in clawed tarsi that aid attachment to fabrics or furniture.

Behavioral clues

  • When disturbed, ticks may crawl slowly, leaving a fine, silvery trail of fecal material.
  • They tend to hide in cracks, under carpets, or on pet bedding where humidity is higher.

Recognizing these characteristics—size range, leg count, coloration changes during feeding, and the presence of a hard dorsal shield—allows accurate identification of a tick encountered inside a residence.