Wild hermit crabs chirp to scare off rivals by rubbing their body parts together or against their shells to make a sound. Also, hermit crabs vibrate within their shells as a warning, so they can hear.
Hermit crabs use their antennae and the sensory hairs on their 10 legs to detect vibrations. However, they can only detect low-to-mid-range frequencies and only those in a nearby radius.
These noises are translated into a sound that hermit crabs use to avoid predators. Since hermit crabs primarily rely on their sense of smell, they don’t need to have good hearing.
Do Hermit Crabs Have Ears?
Hermit crabs don’t have ears, so they respond to sounds with their:
- Antennae
- Legs
It’s difficult to determine how well hermit crabs can hear. Although we can’t give them a test to determine their hearing range, we can observe how they respond to dangers based on sound.
According to Biological Sciences, sounds made by predatory fish alter how marine hermit crabs behave. Instead of foraging for food where the predator is located, it’ll search elsewhere.
Do Hermit Crabs Hear With Their Legs?
Hermit crabs have 10 legs covered with hairs, like tiny antennae, that detect vibrations.
Just like a human’s inner ear translates this into sound, a hermit crab’s legs will take in low-to-mid-range frequencies and interpret them as noise. This enables hermit crabs to:
- Navigate away from predators
- Detect encroaching hermit crabs
- Issue warnings
Vibrations aren’t the only sensory information their hairs can gather.
Using the statocyst structure, hermit crabs can detect changes in balance or orientation. That can help them readjust should they fall over or understand how to balance when climbing over an object.
Do Hermit Crabs Hear With Their Antennae?
Hermits rely on their antennae, just like most arthropods. These appendages are located on their head and intake:
- Temperature differences
- Changes in air pressure
- Vibrations
This allows hermit crabs to detect changes in the weather and hear the world around them. Even if they don’t have good hearing, their antennae can still warn hermit crabs if a predator is nearby.
How Well Can A Hermit Crab Hear?
Hermit crabs don’t have good hearing despite having 10 legs and up to 4 antennae.
Hermit crabs can only detect sounds and vibrations that are rather close by. They’re also deaf to anything beyond a low-to-mid-range frequency.
A hermit crab’s main defense is retreating into its shell. As they spend their days consuming decomposing matter, being able to hear long distance is unnecessary.
However, that doesn’t mean hermit crabs are unaware of their surroundings. Most rely on their sense of smell to pick up where their hearing left off.
A hermit crab’s ability to smell increases in humid environments, especially underwater. So, if a marine hermit crab can’t hear a predator fish from a distance, it may still smell it.
Are Hermit Crabs Sensitive To Noise?
Hermit crabs have a neurological response to a wide range of frequencies, using this ability to avoid enemies. So, if a hermit crab doesn’t think the sound is close by, it may not be concerned.
Also, if it’s a higher frequency sound, the hermit crab may not hear it. Hermit crabs won’t be concerned by the following noises:
- Playing an instrument
- Watching TV
- Listening to loud music
However, if the noise is directly beside the tank, lower frequencies (like a solid bass) may cause hermit crabs distress. Consequently, they may react by moving away or chirping.
If you’re in doubt, play the sound for a few minutes and see how they respond. If they don’t scurry away, chirp, or retreat into their shells, they’re unconcerned by the noise.
Do Hermit Crabs Like Noise?
Hermit crabs have a limited hearing range, so it’s difficult to tell if they like or dislike noise.
After all, when a sound is close enough (and strong enough) to be detected, this means danger is nearby. It can also mean it’s about to fight a rival for its shell.
If this wasn’t the case, and hermits had a broader hearing range, they may enjoy sounds. However, we can conclude that hermits are indifferent to noise.
If it’s far away or too gentle to indicate danger, hermit crabs ignore it. If the noise is nearby, hermit crabs may fear what the sound indicates, not the sound itself.
Can Hermit Crabs Hear Music?
Many hermit crab owners like to play music as entertainment for their pets. While some claim that hermit crabs love it, others observe no reaction.
Their response will largely depend on the kind of music you play.
Strumming a guitar next to your hermit’s enclosure is far more likely to get a reaction than playing a song on your phone because the vibrations are more likely to be registered by a hermit crab.
Likewise, high-pitched music may be outside of a hermit crab’s range of hearing, which means playing the violin may be less impactful than playing the drum.
If you want to experiment with what music your hermit crab can detect, you’ll need to experiment. Adjust the equalizer to increase or decrease the bass and treble.
Can Hermit Crabs Hear You?
The deeper and louder your voice, the more likely the sound will be detected by hermit crabs. Higher-pitch or quiet voices will have little effect.
Hermit crabs will mostly hear you based on your footsteps and movements. Approaching the tank with heavy strides will produce stronger vibrations than a speaking voice. Likewise, tapping your finger on the substrate in the tank will be more impactful than calling a hermit.
The closer you are to the hermit, the more likely it is to hear you. Let the sensory hairs along the hermit crab’s legs and antennae pick up the vibrations. The lower the range of the sound and the heavier the vibration, the more easily a hermit will detect it.
Do Hermit Crabs Make A Noise?
Hermit crabs aren’t silent creatures, but they are quiet pets. They make chirps as a way to communicate.
According to Crustaceana, this can often be interpreted as musical. Some researchers compare it to the strings of a violin being plucked, while others compare it to a bird.
Owners even liken it to a cricket sound, but this depends on the hermit crab. A cricket sound may be more accurate, as hermit crabs use stridulation, which involves rubbing two body parts together.
Even though they produce this sound at night, they can also do so during the day when distressed.
According to the Ecological Society of America, hermit crabs make this sound to defend themselves. Chirping in rapid succession can register as very loud to fellow hermit crabs.
Some owners claim that a chirping noise also indicates excitement. Some also believe that hermit crabs chirp as a mating call. This isn’t entirely true, but you’ll notice hermit crabs making the sound during the mating season. It’s a way to scare off other males.
Do Hermit Crabs Vibrate?
Aside from chirping, hermit crabs know how to communicate using vibrations. According to the Journal of the Marine Biological Association, this usually means rubbing against the inside of their shells.
For example, if one hermit crab is being evicted from its shell by another, it may begin to shake. These tight, controlled vibrations unleash a frequency that the nearby hermit crab not only feels but hears.
If a chirp isn’t enough, a full-bodied shake may do the trick. Depending on the intensity or persistency, the attacking hermit may get annoyed (or scared) and decide to move on.
Hermit crabs don’t have good hearing, but they aren’t deaf. They can detect sounds at a limited frequency range and only sounds that are close by.
