House spiders are common arachnid residents in human dwellings, often belonging to species like the American house spider (Parasteatoda tepidariorum). These small predators are known for their resilience, a trait that allows them to survive in the fluctuating indoor environment. Understanding how long they can survive without food reveals a lot about their biological design. This ability to endure periods of scarcity reflects their evolutionary success.
How Long Spiders Survive Without Food
The duration a house spider can survive without a meal is surprisingly long, typically ranging from several weeks to a few months. Smaller house spiders, such as the common American house spider, can generally last between 30 and 50 days without consuming prey, provided other conditions are favorable. This extended survival is far greater than that of many common household insects.
The maximum fasting period is heavily influenced by the spider’s size and species. While smaller house spiders may reach a limit around 60 days, larger arachnids, such as certain tarantulas, have been documented to survive for six to eighteen months without food. This difference is primarily due to the larger spiders possessing greater internal storage capacity for energy reserves. The age of the spider also plays a role, as mature adults generally endure periods of starvation better than younger spiderlings.
Biological Adaptations for Fasting
Spiders are able to sustain extended fasting periods due to internal biological adaptations focused on energy conservation. As ectotherms, their body temperature and metabolic rate are not internally regulated, meaning their energy expenditure is already lower than that of mammals. During food deprivation, spiders further reduce their metabolic rate, sometimes operating at a mere 30% of their normal activity level.
This metabolic depression allows them to stretch their internal energy reserves, which are primarily stored as lipids, or fat bodies. These lipid stores are utilized first during starvation, preserving muscle tissue for as long as possible. Spiders also possess an efficient circulatory and respiratory system that minimizes energy waste. This combination of a naturally slow metabolism, metabolic depression, and efficient energy storage enables long periods of survival.
Environmental Factors That Change Survival Time
The survival time of a house spider without food is dramatically altered by external environmental variables. Temperature is a major factor, as it directly governs the spider’s metabolic rate. In warmer conditions, the spider’s metabolism increases, forcing it to deplete its stored energy reserves at a much faster pace.
Conversely, cooler temperatures significantly extend survival time because the lower ambient temperature slows down the spider’s internal functions. A spider at 15°C (59°F) may survive nearly twice as long without food as one kept at 25°C (77°F).
The availability of water is more critical than food, as dehydration is often the quickest cause of death. House spiders that have access to water or high humidity can survive for the maximum duration without food. However, without moisture, their survival time can drop to as little as ten to fourteen days, regardless of their prior nutritional status.