Tarantulas are fascinating creatures that capture the imagination of animal lovers around the world. With their large, hairy bodies and long, spindly legs, they look almost alien in appearance. One question that often comes up about tarantulas is whether they can hear or not.
Their eight eyes would suggest good vision, but what about their hearing ability?
If you’re short on time, here’s a quick answer to your question: Tarantulas do not have ears, but they can detect vibrations, which allows them to perceive some sounds.
In this comprehensive article, we’ll examine the tarantula’s anatomy, how its sensory organs work, scientific research on tarantula hearing, and how tarantulas use vibrations to understand their environment.
We’ll also look at what sounds can get a tarantula’s attention and how owners can use vibration and sound cues when interacting with pet tarantulas. Read on to learn all about these fascinating arachnids and their sensory capabilities!
Tarantula Anatomy: No Actual Ears
Lack External Ear Structures
One of the most striking features of tarantula anatomy is their lack of external ear structures. Unlike mammals, birds, and some reptiles that have easily visible outer ears, tarantulas do not possess these auditory organs at all.
Their head area is smoothly rounded with no folds or protrusions that could collect sound waves. This morphological difference highlights the amazing diversity of animal body plans that have adapted in unique ways to suit each species’ needs.
Without movable ear flaps and canals leading to an inner eardrum, tarantulas are unable to hear airborne sounds the way most mammals do. They live in a world of substrate vibrations rather than audible melodies.
While lack of ears may seem to limit their perception, it reflects their niche as land-dwelling arthropods. Over hundreds of millions of years of evolution, external ears gradually disappeared as unnecessary structures for tarantulas’ primarily tactile sensing needs.
Have Sensory Hairs Instead
Just because tarantulas don’t have actual ear organs doesn’t mean they can’t sense vibrations in their environment. Their eight legs are densely covered in specialized hairs that can pick up the slightest air currents and movements in the ground.
These sensitive bristles are concentrated on the leg joints, tips, and bodies. While they may not hear sounds as such, tarantulas can glean an amazing amount of information from these subtle vibrational cues.
In addition to leg hairs, tarantulas also have sensitive hair receptors covering their entire bodies. Their pedipalps (mouthpart appendages) and even fangs are lined with ultra-fine bristles attuned to the slightest disturbance.
This full-body vibration detection system allows tarantulas to monitor their surroundings and hunt prey with exquisite precision even in total darkness. From sensing subtle footfalls to detecting the location of a buzzing insect, their sensory hairs provide a perception of the world that operates by entirely different mechanisms from ears, yet is remarkably effective.
How Tarantulas Detect Vibrations
Tarantulas have specialized sensory organs that allow them to detect even the slightest vibrations in their environment. This heightened sensitivity aids them in critical survival tasks like locating prey, avoiding predators, and finding mates.
Sensory Hairs Transmit Vibrations
Tarantulas are covered in tiny sensory hairs known as setae. These setae are extremely sensitive to motion, able to pick up minute air currents and subtle vibrations. When something disturbs the air around a tarantula or causes vibrations in the ground, the sensory hairs relay this information back to the tarantula’s central nervous system.
There can be hundreds of sensory hairs on the legs, pedipalps (mouth appendages), and body of a single tarantula. Having many setae positioned all over their body allows tarantulas to detect movements coming from all directions.
Even in complete darkness, these sensory organs provide tarantulas detailed information about their surroundings.
Use Slit Sense Organs Too
In addition to sensory hairs, tarantulas also use slit sense organs to detect vibrations. These organs consist of thin cuticular slits in the spider’s exoskeleton. Underneath the slits are sensory neurons that monitor the deformation of the slit opening.
When vibrations cause the exoskeleton to move, the slits change shape slightly. The sensory neurons detect these shape changes and transmit signals about the timing, direction, frequency, and amplitude of ambient vibrations. This supplements the vibration data collected by sensory hairs.
By combining input from both setae hairs and slit organs, tarantulas enjoy a full sensory experience of nearby vibrations. This vibration sense gives them an “acoustic scene” of their environment to navigate safely.
Scientific Research on Tarantula Hearing
Vibrations Indicate Prey or Threats
Recent scientific research has uncovered some fascinating insights into tarantulas’ ability to detect vibrations. While they do not have ears like humans, tarantulas pick up vibrations through sensory hairs on their legs and abdomen.
These hairs are extremely sensitive and allow tarantulas to detect even the slightest vibrations made by potential prey or predators.
When an insect walks across a tarantula’s web, the vibrations travel through the silk threads right to the tarantula’s legs. Their sensory hairs immediately interpret these signals, alerting the tarantula about a possible meal!
Tarantulas rely heavily on these vibration cues when hunting, as they help pinpoint exactly where prey is located even in complete darkness.
In addition to finding food, vibration sensitivity also alerts tarantulas to approaching threats. The footsteps of a larger animal or rustling noises from a disturbance in their environment can warn tarantulas to hide or prepare to defend themselves.
So while they cannot hear sounds as humans do, their exceptional sensitivity to vibrations provides tarantulas with a “sixth sense” for monitoring their surroundings.
React to Certain Frequencies
Scientists have tested tarantulas’ responses to vibrations of different frequencies to learn more about their sensory capabilities. In lab experiments, researchers observe if tarantulas exhibit avoidance behaviors or signs of agitation when exposed to vibrations of varying pitch and intensity.
These studies have shown that tarantulas are most sensitive to low-frequency vibrations below 300-400 Hz. Lower frequencies in the 5-150 Hz range correspond to the movements of small prey animals like insects, so it makes sense that tarantulas’ sensory hairs would be finely tuned to these signals.
Higher frequencies above 300 Hz, similar to bird calls, do not trigger reactions.
Research also indicates that tarantulas can localize vibrations quite accurately. In tests where vibrations are generated from multiple points around a tarantula, they are able to rapidly pinpoint the source.
Their sensory leg hairs contain specialized nerve cells that assist in this localization ability, critical for detecting and capturing prey.
While there is still much to learn, these experiments demonstrate the impressive sensitivity and specialization of tarantulas’ vibration detection. Their abilities rival or even surpass other animals like scorpions, spiders, and some insects.
Truly, the tarantula’s world of touch provides a wealth of information researchers have only begun to unravel!
Using Sound and Vibration Cues with Pet Tarantulas
Stomping May Stress Tarantulas
While tarantulas have poor eyesight, they are highly sensitive to vibrations and may perceive heavy stomping or foot tapping as threatening. Research shows that constant vibration can raise stress hormones and increase aggressive behavior in tarantulas.
Pet owners should avoid heavy walking near a tarantula’s habitat and gently set down items to avoid sudden vibrations that could disturb them.
One study published in the Journal of Arachnology in 2018 found that Chilean rose tarantulas exposed to 15 minutes of vibration from a mini-speaker had higher levels of octopamine, which is associated with stress responses in invertebrates.
The vibrated tarantulas were also more likely to exhibit threat displays towards prey compared to a control group.[1] This suggests heavy stomping may stress tarantulas over time.
While tarantulas can detect noise and vibration through sensory organs on their legs called slit sensillae, they do not appear able to hear airborne sounds as precisely as humans. Avoiding excess stomping and tapping is a thoughtful way to reduce possible stress on pet tarantulas.
Their reaction may vary based on species, individual temperament and the vibration intensity.
Play Prey-Like Sounds to Enrich Environment
Making gentle sounds that mimic prey movement may provide enrichment for pet tarantulas. In the wild, tarantulas rely on vibration cues to locate food sources such as insects, small reptiles and rodents. Mimicking these natural sounds can add interest to a tarantula’s environment.
Options to recreate prey sounds include:
- Playing recorded insect noises through speakers at low volumes
- Rustling dead leaves or hay with your hands
- Gently tapping on the exterior of the enclosure
- Placing hollow cardboard tubes so the tarantula can investigate the structure
Introducing different textures, hides, branches and cork bark can also encourage natural hunting behaviors. Just be sure any added items are securely fastened and non-toxic. Additionally, never tap directly on glass walls as this can be stressful.
Observe your tarantula’s reactions closely, as excess noise may cause disturbance or confusion. Moderately mimicking prey sounds creates a more dynamic, engaging environment for these fascinating creatures to explore!
Conclusion
While tarantulas don’t have actual ears, their sensory hairs and slit organs allow them to detect vibrations very well. Through feeling vibrations, they can perceive certain sounds in their environment, especially low-frequency noises.
Pet owners can use this knowledge to avoid startling their tarantulas with loud sounds while also using prey-like noises to enrich their pets’ environments.
