Fleas Anatomy and Physiology
Fleas do not have a heart. Their internal fluid circulates nutrients and hormones. Fleas breathe through spiracles and trachea – small holes leading to tubes that deliver oxygen directly to cells. Beside their role as ectoparasites, fleas can transmit pathogens to humans and animals. Fleas commonly bother dogs and cats.
Fleas Life Cycle
Adult fleas lay eggs which hatch into larvae. Larvae get everywhere – in carpets, floorboards, upholstery and pet bedding. Fleas can jump around 30cm high. Insects have an open circulatory system with a heart that pumps fluid called hemolymph throughout the body.
Fleas Comparison with Other Insects
The morphology of cat fleas is similar to dog fleas, but cat fleas have a sloping forehead. The hind tibia of cat fleas lacks an outer apical tooth. Human fleas are slightly larger than dog and cat fleas. Human fleas occasionally transmit pathogenic plagues like Yersinia pestis.
Emotions in Insects
Flies likely feel emotions like fear. The fly heart is a muscular tube running along the abdomen. The human heart is a muscular organ with multiple chambers and valves. Both pump blood, but work differently.
Conclusion
The human flea is the most common flea. It can carry plague bacteria and cause skin lesions. Despite the name, cat fleas live on many animals, sometimes humans.