Spiders, often perceived as creatures that instill fear, also exhibit instinctive avoidance responses to environmental threats. This survival mechanism guides them away from life-threatening dangers or unsuitable habitats. Understanding these aversions provides insight into the intricate ways spiders interact with their surroundings and the challenges they face.
Natural Predators
Spiders face a variety of biological threats from other animals that actively hunt them. Birds are prominent predators, with many insectivorous species such as wrens, sparrows, robins, and blackbirds regularly consuming spiders as part of their diet. Some birds, like great-tits, even feed spiders to their young.
Reptiles and amphibians also prey on spiders. Lizards such as geckos, chameleons, and anoles are known to hunt spiders. Frogs and toads frequently ambush spiders, especially near water sources. Additionally, fish will consume spiders that accidentally fall into the water, with species like trout and mosquitofish known to feed on them.
Insects, particularly certain wasps, pose a unique threat to spiders. Spider wasps (Pompilidae), including the well-known tarantula hawks, are specialized predators that paralyze spiders with a sting before laying an egg on or near them. The wasp larva then feeds on the immobilized spider. Other arachnids, like scorpions and centipedes, also prey on spiders, along with larger spider species themselves, as some engage in cannibalism.
Environmental Aversions
Spiders exhibit avoidance behaviors towards certain environmental conditions and strong sensory stimuli. They are highly sensitive to vibrations, which they detect through specialized slit sensillae on their legs. These sensillae allow them to interpret movements in their webs and surroundings, helping them locate prey, find mates, and avoid predators. Loud noises, which create air vibrations, can cause spiders to retreat.
Strong odors also serve as significant deterrents for spiders. They use their legs to smell and taste, making them averse to potent scents. Peppermint oil, for instance, contains compounds like menthol and menthone that spiders find particularly unpleasant, disrupting their sensory receptors. Citrus oils, including lemon and orange, are also known to repel spiders, likely due to their acidic nature and strong aroma.
Other scents that spiders tend to avoid include lavender, eucalyptus, tea tree oil, cedar, and even white vinegar. These smells create an undesirable environment for spiders, prompting them to seek more favorable locations. Clean and undisturbed spaces are generally less appealing to spiders, as they prefer cluttered areas that offer more hiding spots and opportunities to build webs. Human-applied deterrents often leverage these aversions by introducing strong smells or maintaining tidiness to make an area less hospitable.