flea jumping two hundred times its own body length
- Size
- Length: 1–4 mm
- Lifespan
- 1–2 years
- Diet
- Haematophagous: adults feed exclusively on blood of birds, mammals and occasionally reptiles. Larvae feed on organic debris, dried blood and faeces in host nests or bedding.
- Habitat
- Wherever their hosts reside, from dry bedding of a family dog to nests of native birds and bats. Larvae live in carpets, pet bedding, soil and nest debris.
- Range
- Throughout North and South Islands wherever host animals live, including homes, farms, wildlife burrows and bird nests. Most common in urban and suburban areas with pets.
- Endemism
- Introduced
- Main Threats
- None. This introduced pest is widespread. Controlled using pet treatments and household insecticides, though some populations have developed resistance to common chemicals.
- Population
- While most common species are introduced (cat and dog fleas), New Zealand has several fascinating native fleas specialised for unique birds and only native mammals (bats).
- Conservation Status
- Introduced
The Olympic jumper of the microscopic world. A flea that can jump 100 times its own height.
The flea has an anatomy radically laterally compressed, flattened from side to side, to slip between dense hairs or feathers with ease. Having entirely abandoned the power of flight millions of years ago, they have evolved massive hind legs powered by a specialised elastic protein called resilin. A flea that is a spring.
This biological material acts like a high-tension spring, storing energy that when released launches the insect hundreds of times its own body height in a fraction of a second. This extreme elasticity is a survival masterstroke, allowing a wingless creature to intercept fast-moving hosts or escape predators with acceleration that far exceeds the structural limits of ordinary muscle.
Specialised hitchhikers possess a suite of sensory organs tuned to detect the heat, carbon dioxide and vibrations of a passing host. Their mouthparts are a sophisticated toolkit designed for piercing skin and injecting an anticoagulant to ensure a steady flow of blood.
Different species of fleas have meticulously adapted to the specific skin textures and grooming habits of birds, rodents or domestic mammals. Their eggs are often laid directly on the host but quickly roll off into the surrounding environment such as a nest or a carpet where the worm-like larvae feed on organic debris.
This strategy ensures that even if the adult is groomed away, a new generation of invisible jumpers is already waiting in the shadows to reclaim their place. As an introduced species in New Zealand, the common cat and dog fleas are primarily associated with human-modified environments.
To encounter a flea is to witness a survivor that has traded the vastness of the sky for a high-speed, high-stakes life on a living landscape. The cat is warm. The flea jumps, a tiny spring, landing in the fur. It bites. It drinks. It jumps again. The cat scratches. The flea is gone. It does not know it is a champion jumper. It does not know it traded the sky for fur.
It just wants blood. Even the smallest invader can possess a level of structural resilience that defies its diminutive size. The flea is proof.