How does a tick look? - briefly
A tick is a small, oval arachnid roughly 2–5 mm long, dark brown or reddish, with a flattened dorsal surface and eight legs. After feeding, its body expands into a rounded, balloon‑like shape up to about 10 mm.
How does a tick look? - in detail
Ticks are small arachnids, typically ranging from 2 mm to 5 mm in length when unfed. Their bodies consist of two main regions: the anterior capitulum, which houses the mouthparts, and the posterior idiosoma, covered by a hardened dorsal shield called the scutum in many species.
The capitulum includes the chelicerae and hypostome, structures adapted for piercing skin and anchoring to the host. The hypostome is barbed, facilitating a firm attachment during blood feeding. The palps are short, sensory appendages positioned beside the mouthparts.
The idiosoma is divided into a dorsal scutum and a ventral region. The scutum is a dark, oval plate, often brown or black, and may be smooth or bear faint punctate markings. In females of certain species, the scutum covers only a portion of the dorsal surface, allowing the abdomen to expand dramatically when engorged. Engorged individuals can increase in size up to 10 mm in length and become noticeably swollen, with the abdomen turning a lighter, reddish‑brown hue as it fills with blood.
Legs are eight in number, arranged in four pairs. Each leg ends in a claw that grips the host’s fur or skin. The legs are relatively long compared to the body, giving the tick a slightly elongated appearance. Leg segments are articulated, permitting movement and attachment adjustments.
Key visual characteristics can be summarized:
- Size: 2–5 mm unfed; up to 10 mm when engorged.
- Color: dark brown to black dorsally; lighter, reddish abdomen after feeding.
- Dorsal shield (scutum): oval, often smooth, covering whole back in males, partial in engorging females.
- Mouthparts: protruding capitulum with barbed hypostome.
- Legs: eight, each with terminal claws, relatively long.
These features distinguish ticks from other small arthropods and enable accurate identification in field or laboratory settings.