Final answer:
Adult fleas need a warm-blooded host to survive, not specifically a human or fur-bearing host. They are ectoparasites that feed on blood and other substances from the host.
Step-by-step explanation:
Adult fleas require a warm-blooded host to survive and thrive. These ectoparasites are specialized in inhabiting the surface of their host for at least part of their life, consuming resources such as blood, secretions, and other organic material derived from the host.
While fleas can be found on a range of warm-blooded hosts, including humans, they do not specifically require a human or fur-bearing host to survive. Nevertheless, they do need to establish contact with a suitable warm-blooded host to complete their life cycle and reproduce effectively.