What do bedbugs feed on when there are no humans? - briefly
In the absence of humans, bedbugs obtain blood from other warm‑blooded hosts such as rodents, birds, dogs, or cats. They can survive for weeks or months without feeding but do not resort to non‑animal food sources.
What do bedbugs feed on when there are no humans? - in detail
Bed bugs (Cimex lectularius) are obligate blood‑suckers; without a human presence they turn to any available vertebrate that supplies warm, flowing blood. Typical alternative hosts include domestic pets such as dogs and cats, peridomestic mammals like mice and rats, and avian species that roost in attics or barns. In wildlife‑infested structures, bats provide a reliable source, especially where colonies occupy roof spaces. Reptiles and amphibians are rarely exploited because their blood temperature is lower than the bug’s preferred range, reducing feeding efficiency.
When a preferred host is absent, bed bugs can endure extended periods without a meal. Adult females may survive up to 300 days, while nymphs can persist for several months, relying on reduced metabolic rates and periodic opportunistic feeds. During these intervals, the insects may:
- Seek out fleeting contacts with passing mammals (e.g., rodents entering a shed).
- Exploit accidental encounters with birds nesting in the building.
- Feed on dead hosts if carrion is present, though this is not a primary strategy.
Host‑location cues remain consistent across species. Bed bugs detect carbon dioxide exhaled by warm‑blooded animals, sense body heat gradients, and respond to kairomones released from skin. These sensory mechanisms allow rapid adaptation to non‑human hosts, ensuring continued reproduction and colony maintenance.
Reproductive output adjusts to the quality of the blood meal. Blood from larger mammals typically yields higher protein content, supporting greater egg production than avian or rodent blood. Nevertheless, the insects can complete a life cycle on any suitable vertebrate source, provided the host remains accessible for periodic feeding.
In summary, in the absence of people, bed bugs subsist on the blood of other mammals, birds, and occasionally bats, exploiting any warm‑blooded animal that enters their environment. Their physiological capacity for prolonged starvation and flexible host‑seeking behavior enables the species to persist until a human host becomes available again.