How many antennae does a flea have? - briefly
Fleas have a single pair of antennae, meaning they possess two antennae in total.
How many antennae does a flea have? - in detail
Fleas possess a single pair of antennae, giving them two sensory appendages. Each antenna consists of three primary segments: the scape, pedicel, and a multi‑segmented flagellum. The scape attaches to the head capsule, the pedicel contains the Johnston’s organ for detecting movement, and the flagellum bears numerous sensilla that perceive chemical cues, humidity, and temperature.
Key characteristics:
- Length: Typically 0.3–0.5 mm, proportionally short relative to the flea’s body.
- Structure: Cuticular exoskeleton with flexible joints, allowing limited motion.
- Function: Primary role in host detection; chemoreceptors identify host odorants, while mechanoreceptors respond to air currents and vibrations.
- Development: Antennae develop during the larval stage and are retained through pupation and adulthood without significant morphological change.
- Comparison: Unlike many holometabolous insects that have elongated, multi‑segmented antennae, flea antennae are compact and adapted for a parasitic lifestyle.
The two‑antenna configuration aligns with the typical insect plan, where a single pair provides sufficient sensory input for the flea’s rapid jumping and host‑seeking behavior.