What does a common tick look like? - briefly
A typical tick is a small, oval arachnid about 2–5 mm long when unfed, featuring a dark brown or reddish‑brown scutum on its dorsal surface and eight legs. After feeding, its abdomen swells into a pale, balloon‑like shape that can reach up to 10 mm.
What does a common tick look like? - in detail
A typical tick is a small arachnid measuring 2–5 mm when unfed. Its body consists of two main sections: the anterior capitulum (mouthparts) and the posterior idiosoma, which is covered by a hard dorsal shield called the scutum. The capitulum bears the chelicerae, a barbed hypostome for anchoring to the host, and palps used for sensory detection. The scutum is dark brown to black, slightly oval, and may display a faint pattern of lighter spots depending on the species.
The legs are eight in number, arranged in four pairs. Each leg ends in a claw that can grip hair or fur, facilitating attachment. In an unfed state the legs are relatively short; after a blood meal they lengthen as the body expands.
Coloration varies with feeding status. An unfed tick appears uniformly dark, while a engorged female can swell to 10 mm or more, turning reddish‑brown as the abdomen fills with blood. Males retain a relatively flat shape and remain dark throughout feeding.
Key morphological details for each developmental stage:
- Larva (seed tick): six legs, 0.5–1 mm long, translucent to light brown, no scutum.
- Nymph: eight legs, 1.5–2 mm, reddish‑brown, small scutum covering part of the dorsal surface.
- Adult female: eight legs, 3–5 mm unfed, large scutum covering the entire dorsal surface, abdomen expands dramatically when engorged.
- Adult male: eight legs, 2–3 mm, scutum covers most of the dorsal surface, abdomen remains narrow during feeding.
The hypostome’s barbs are visible as a small, dark, pointed structure beneath the capitulum. The ventral side of the idiosoma bears the anus and genital aperture, which are concealed beneath the scutum in females and exposed in males.
Overall, a common tick presents a compact, oval silhouette, dark coloration, a distinct shield on the back, eight jointed legs, and a protruding mouthpart complex designed for piercing skin and securing blood meals.