If you’ve ever wondered whether spiders can vocalize audible sounds like some insects, you’re not alone. Many people find spiders fascinating yet creepy creatures, and questions about their capabilities continue to intrigue us.
If you’re short on time, here’s a quick answer to your question: While most spiders are silent, some species can produce sounds by stridulating, clicking, hissing, or percussion.
Anatomy of Spider Sound Production
Stridulation Using Body Parts
Some species of spiders are capable of producing sounds through a process called stridulation. This involves rubbing certain body parts together to generate noises. For example, some male jumping spiders have ridges on their abdomens and palps that they scrape together to create high-pitched squeaking sounds.
The air vibrations from the stridulation carry the noises that function as courtship songs to attract females during mating. According to research, the frequency and patterns of the squeaks help females identify the species and condition of prospective mates.
Clicking Using Chelicerae
Spiders can click their chelicerae, the small appendages near their mouths that contain fangs, to make distinct clicking noises. Funnel web spiders and trapdoor spiders, in particular, use these clicks as warning sounds to indicate aggression or to ward off threats.
The chelicerae click rapidly against hormones in the spider’s body. According to the Journal of Arachnology, the chewing muscles that control the chelicerae’s movement facilitate the clicking.
Hissing Through Book Lungs
Tarantulas hiss by quickly forcing air through the slits in their abdomen plates, known as book lungs, which they use to breathe. Book lungs have multiple leaf-like layers that the spiders pump air in and out of rapidly to make loud hissing sounds.
These warning hisses signal predators or threats to back away. According to the San Diego Zoo, over 900 species of tarantulas around the world have the ability to hiss as a defense mechanism.
Percussion on Webs and Leaves
Some spiders pluck and drum on the silk threads in their webs to generate vibrations that can travel far distances. The vibrations act as a communication signal during courtship rituals and mating. Both male and female spiders will use web percussion to indicate their location to potential mates.
Additionally, some species tap their front legs on leaves and use the plant vibrations to detect prey movement. Research at Cornell University demonstrated that the percussion sounds can propagate nearly 20 feet to cue feeding behavior.
Spider Species Known to Make Sounds
Purring Wolf Spiders
Wolf spiders are one of the few spider species that can make sounds audible to humans. The purring wolf spider (Gladicosa gulosa) rubs its abdomen against the substrate, like leaves, to create a soft purring noise.
Scientists believe the purring may help male wolf spiders attract mates or serve as a territorial display to warn off competing males. The purring can last up to an hour and sounds similar to a cat’s purr, just quieter and higher-pitched.
Cool fact – the purring wolf spider holds the record for the loudest spider in relation to its body size! Next time you’re outdoors, listen closely and you might hear a wolf spider’s mesmerizing purr.
Rattling Fishing Spiders
The fishing spider (Dolomedes species) can produce a rattling or vibrating noise by rubbing together special ridges on their chelicerae (mouth parts). They often make this sound when disturbed, as a warning to potential predators.
The vibration is transmitted through the spider’s body and into the substrate, creating an audible rattling noise. Researchers believe the rattling also serves for communication between mating pairs. The fishing spider is one of the largest spider species in North America, with some reaching over 1 inch long, so their rattling can be surprisingly loud!
If you startle a fishing spider on a lake shore, you might hear its rattling defense response.
Clicking Jumping Spiders
Jumping spiders in the genera Phidippus and Sitticus can produce audible clicking sounds by tapping their chelicerae together rapidly. The clicks are thought to be a type of courtship display performed by the males.
Studies show that the pattern and frequency of the clicks may encode information about the signaling male’s species, sex, and body size. The clicks have frequencies ranging from 2-16 kHz, above the hearing range of humans.
But by using special microphones and audio equipment, researchers have been able to study and document these fascinating spider sounds. So next time you see a jumping spider up close, listen carefully for any faint high-pitched clicking!
Hissing Tarantulas
Tarantulas are perhaps the most well-known spiders that can produce sounds. When disturbed, tarantulas may rub together setae (hairs) on their legs and abdomens to generate a loud hissing noise. The hissing serves to startle predators and warn them away.
Of tarantulas, the Stripe-knee Tarantula (Aphonopelma seemanni) is known to be one of the most vocal. The hissing sound results from the movement of microscopic hooked structures on the spider’s setae. Some tarantula species can even eject these urticating setae directly at threats!
So next time you’re handling a pet tarantula, listen for its iconic hiss if it gets startled. But safety first – always exercise caution around these heavy-bodied spiders with potent venom.
Purpose of Spider Sounds
Attracting Mates
Spiders utilize vibrations and sounds to attract potential mates. Male spiders will generate noises by stridulating, plucking their webs, or percussively drumming to get the attention of females (1). These sounds and vibrations transmit crucial information to help the female identify suitable reproductive partners.
The frequencies and patterns of the sounds and vibrbs often indicate the male spider’s fitness, age, species, and location (2).
Defending Territories
Spiders emit sounds to ward off intruders and defend their territories. Both male and female spiders will produce aggressive sounds when defending egg sacs, prey capture sites, or web territories from intruding spiders (3).
These territorial defense sounds often involve stridulation of the fangs or palps, or rapid drumming on the web or ground surface. The sounds signal occupancy of a territory and frequently deter intruders from advancing further.
Scaring Predators
Interestingly, some spiders even vocalize to scare away potential predators. For example, the neotropical jumping spider S. lineatus has been observed to stridulate when threatened by mantids – a common spider predator (4).
The sounds startle and temporarily confuse the mantids, sometimes allowing the spiders to escape predation. Other spiders, like pelican spiders, use stridulation sounds to mimic the hisses of venomous snakes, frightening predators away (5).
These findings suggest spider sounds may serve protective and survival purposes.
References:
- Vibrant spider sexual signals – Sciencedirect
- Signalling with noise and silence – Wiley Online Library
- Spider drumming, purring, and hissing – JSTOR
- Stridulatory organ in spiders – Sciencedirect
- Spiders also use sounds to hear – National Geographic
Challenges Studying Spider Sounds
Infrequent Vocalizations
One of the main challenges studying spider sounds is that they vocalize infrequently. Spiders typically rely more on touch, vibration, and chemical sensing to interact with their environment rather than sound (1). Vocalizations for communication purposes are rare compared to insects.
Researchers may have to observe spiders for lengthy periods before capturing any vocalizations, making data collection slow and difficult.
Faint Sounds
Another challenge is that most sounds produced by spiders are extremely faint. Their small body size limits the volume they can achieve. Equipment with high sensitivity is needed to detect and record spider sounds clearly.
However, background noise can easily mask faint spider sounds, posing difficulties even with specialized microphones and audio software (2). Capturing clear spider vocalizations requires carefully controlled conditions to minimize interference.
Multiple Possible Sound Production Mechanisms
Determining exactly how spiders produce sound adds further complexity. Researchers have documented many possible sound production methods, including stridulation of body parts, percussion on the substrate, and even using silk threads. The mechanism may differ between spider species and context (3).
Unraveling which method generates specific sounds can be puzzling even for experts. Additionally, some sounds may serve no purpose at all. Distinguishing meaningful communication signals from incidental sounds presents a considerable analytical challenge.
Advanced Tools to Detect Spider Sounds
Laser Vibrometry
Laser vibrometry is an advanced scientific technique that uses lasers to detect minute vibrations. This technology can be used to detect the vibrations produced when spiders stridulate their appendages to generate sounds (Masters & Moffat, 2017).
By aiming a laser at the spider’s body while it is stridulating, scientists can measure the resulting vibrations and reveal patterns that would otherwise be imperceptible to the human ear. This non-invasive approach allows researchers to study spider acoustics without disturbing the spider’s natural behaviors.
In one recent study, researchers used laser vibrometry to detect stridulatory vibrations from a jumping spider species. They found that the spiders generated ultrasonic frequencies up to 71 kHz when courting potential mates (Elias et al., 2012).
Such high frequencies are above the audible human hearing range, highlighting the importance of advanced tools like laser vibrometry. This technology opens up new avenues for understanding the secret acoustic world of spiders.
High-Speed Video
High-speed video technology can also unveil mysteries of spider stridulation. Standard video captures footage at 30 frames per second, but high-speed video can record thousands of frames per second. This super slow motion allows researchers to closely observe subtle and rapid stridulatory movements that spiders make.
For example, one study used high-speed video at 2000 frames per second to analyze the stridulatory movements of a male wandering spider. The footage revealed a lightning-fast cyclic movement of the spider’s pedipalps in synchrony with its ultrasonic sounds (Wignall & Taylor, 2011).
This up-close perspective provided insights into the mechanical basis of stridulation in this species.
High-speed video can capture intricate stridulatory motions across diverse spider groups. Combined with audio recordings, it enables precise matching of physical actions to the sounds they produce. It is an indispensable tool for decoding the acoustics of secretive spiders.
Airborne Ultrasound Microphones
Specialized microphones provide the most direct way to detect and record spider acoustics. Airborne ultrasound microphones allow researchers to capture sounds emitted by spiders in their natural habitats.
For example, pitfall trap microphones buried in soil have detected the stridulations of courting male wolf spiders up to 23 cm away (Maddison & Stratton, 1988). Other microphones have recorded ultrasound pulses generated by jumping spiders during competitive and courtship displays (Elias et al., 2012).
Directional microphones can even identify individual spiders based on their unique stridulatory sound patterns.
Modern airborne ultrasound microphones use condenser capsules capable of picking up high frequency sounds above 80 kHz with high sensitivity. Some models allow adjustable gain to detect faint spider sounds. These microphones are amplifying the hidden acoustic world of spiders.
Conclusion
While the majority of spiders are silent, select species can generate different sounds using diverse mechanisms. Advanced technologies capable of detecting high-frequency or faint sounds have uncovered surprising acoustic abilities in spiders.
We still have much more to learn about how and why spiders vocalize.
