Spiders are often considered silent creatures, a misconception stemming from their lack of lungs or vocal cords. While they cannot “vocalize” in the human sense, spiders are highly communicative organisms that produce sounds and vibrations for various purposes. These acoustic signals are a fundamental part of their complex behavioral ecology, enabling them to navigate social interactions and environmental threats. The mechanical sounds they create are integral to their survival, even if many are undetectable to the unaided human ear.
Yes Spiders Create Sound
Spiders create a variety of acoustic signals, which generally fall into two categories based on how the sound travels. The most common form of communication involves substrate vibrations, which are signals transmitted through a solid surface like the ground, a leaf, or a web strand. These vibrations are sensed by the spider’s specialized mechanoreceptors and are the primary way they communicate. Some species also produce airborne sounds, which are vibrations that propagate through the air and can sometimes be heard by humans, such as a large tarantula rubbing its legs together, creating a hissing noise. The majority of spider communication relies on the transmission of low-frequency vibrations across the substrate, which are undetectable to humans.
Methods of Acoustic Production
Spiders have evolved several specialized anatomical methods for generating these acoustic signals, the two most common being stridulation and percussion.
Stridulation is a mechanical process where the spider rubs two distinct body parts together, functioning much like a washboard and scraper. One part, often called the “file,” features a series of fine ridges, while the other, the “scraper,” is a stiff projection or set of bristles. Scraping these two surfaces together creates vibrations, resulting in sounds that can range from a faint chirp to a distinct hiss, depending on the species. For instance, some tarantulas use stridulation by rubbing bristles on their legs against their chelicerae, or jaws, to produce a loud defensive sound.
Percussion, or drumming, is a second common method, where the spider intentionally taps a body part against the substrate to create vibrations. Male wolf spiders are well known for this behavior, rhythmically beating the ground with their pedipalps, which are small, leg-like appendages near the mouth. This drumming creates a species-specific seismic signal that travels through the earth or leaf litter. Some species also employ abdominal percussion, rapidly thumping their abdomen against the ground to generate a signal that can serve as a territorial marker.
Why Spiders Use Sound
The mechanical sounds and vibrations spiders produce serve specific functions related to survival and reproduction.
Courtship rituals are a primary driver for acoustic signaling, as males must announce their presence to females without being mistaken for prey. Male spiders deploy species-specific drumming patterns or stridulatory sounds to identify themselves to a potential mate, with the female assessing the male’s suitability based on the signal’s rhythm and intensity.
Sound is also used for defensive warnings and territorial communication. Large spiders, such as the Goliath tarantula, use loud stridulation to produce a hissing noise when disturbed, which serves as an auditory warning to potential predators. Acoustic signals are also employed in territorial disputes, where spiders use abdominal percussion to send low-frequency vibrations across the ground, announcing their presence and claiming an area. Female spiders can also use vibrations to communicate with their own young, guiding spiderlings to safety or food within a nursery web.