What does a bedbug feed on if there is no human? - briefly
«Bedbugs» survive by feeding on the blood of alternative warm‑blooded animals such as birds, rodents, dogs or cats when humans are unavailable. They can endure weeks without a meal, but prolonged starvation leads to mortality.
What does a bedbug feed on if there is no human? - in detail
Bedbugs are obligate hematophagous insects; they require vertebrate blood for development and reproduction. In the absence of a human host, they turn to other warm‑blooded animals that emit the cues they use for host location, such as carbon dioxide, heat, and specific skin odors.
Common alternative hosts include domestic pets (cats, dogs), laboratory animals (guinea pigs, rabbits), and peridomestic mammals (rats, mice, squirrels). Birds that enter indoor spaces—pigeons, sparrows, or pet birds—also provide suitable blood meals. Wildlife such as bats or raccoons may be exploited when they roost in attics or crawl spaces. Each of these hosts supplies the protein and lipids required for egg production and molting.
Bedbugs detect hosts through a combination of sensory mechanisms. Thermoreceptors guide them toward temperature gradients typical of endothermic bodies. Chemoreceptors respond to volatile compounds on skin and hair, while CO₂ receptors trigger activation when a potential host exhales. These cues operate regardless of species, allowing the insect to locate non‑human blood sources.
When suitable hosts are scarce, bedbugs can endure prolonged fasting periods. Laboratory observations record survival for up to 400 days without feeding, during which metabolic rates decline and activity diminishes. This capacity enables populations to persist in vacant dwellings until a new host becomes available.
In summary, without humans, bedbugs feed on a range of mammals and birds that provide the necessary blood. Their host‑seeking behavior relies on universal physiological signals, and their ability to survive extended starvation supports continued existence in environments lacking their preferred host.