Last Updated on: 19th October 2023, 02:14 pm
Hermit crabs can stridulate, which is described as a cross between a chirping cricket and a croaking frog. If you were holding the hermit crab at the time, you’d likely detect the shell vibrating.
Stridulation is done to ward off competition for shells or mating rights by rivals or denote discomfort or agitation. Some hermit crabs also chirp when afraid or overstimulated.
If hermit crabs are silent, this suggests they’re feeling happy and contented.
How Does A Hermit Crab Chirp?
The method by which hermit crabs stridulate is not well understood.
One theory is they knock their legs together or scrape a leg against their shell. Some people report hearing chirping when the walking legs are still, suggesting they use their 4 rearmost legs.
The penultimate pair of legs toward the rear are most likely to be used for stridulation.
The shell amplifies the sound, making it easy for other hermit crabs to hear. The sound produced varies based on the shell’s thickness, size, and shape.
Why Is My Hermit Crab Chirping?
Reasons why hermit crabs chirp include:
- Fear.
- Deterrence.
- Aggression.
- Stimulation.
- Discomfort.
As you can see, this is a broad number of definitions. The question, “Why do hermit crabs chirp?” has no definitive scientific answer, but several explanations exist. These include:
Deterring Rivals
One form of hermit crab stridulation is vibrating, which is undertaken to warn rival hermit crabs away from a coveted shell. Along with potential mates, shells are a leading source of confrontation.
Males, in particular, often clash over shells because they grow so fast, completing several molts in their earliest years. This leaves hermit crabs constantly seeking bigger, better shells.
Hermit crabs aren’t shy about challenging others for a new shell.
If a hermit crab wants a shell that belongs to another hermit crab, it’ll start shell rapping. This is the act of clashing shells, trying to force the occupant into the open to do battle.
According to Biology Letters, the owner of the shell will start to vibrate inside, which is a display of strength and authority. The owner of the shell is attempting to deter its opponent.
The challenger will react accordingly. The aggressor will continue shell rapping if it’s sufficiently confident or desperate. If not, it’ll walk away and seek an easier opponent.
Inter-Species Aggression
Hermit crabs engage in conflict over shells. In most instances, this will be civil, but there can be a thin line between negotiation and aggression.
According to Animal Behavior, aggressive hermit crabs can evict rivals from a shell by force, often accompanied by increasingly loud chirping.
Both hermit crabs are communicating their displeasure with the actions of the other.
Most hermit crabs co-exist peacefully, especially hermit crabs of the same species. Aggression can occur because every hermit crab is unique, and some are more antagonistic than others.
If you have one hermit crab that seems overly hostile, consider rehousing it separately.
Expressing Fear
Hermit crabs are believed to stridulate when afraid. A loud, squawking chirp is an expression of fear.
Hermit crabs can fight over shells, but not all are prepared to fight. For example, a tiny hermit crab may be frightened by the aggressive behavior of a larger rival.
Also, check for external threats. If you own other pets, like cats or dogs, ensure they’re not patrolling the hermit crab tank because this can frighten the occupants.
Check the hygrometer to ensure the humidity level is appropriate. If hermit crabs experience dry gills, they’ll struggle to breathe and eventually die due to suffocation.
Agitation And Annoyance
Hermit crabs chirp when disturbed or if something displeases them.
Common examples of when you may hear hermit crabs chirp include:
- Disturbing sleeping hermit crabs.
- Moving hermit crabs from their habitat.
- Picking up a hermit crab that doesn’t want to be handled.
- A tankmate climbs over the top of a prone hermit crab.
- Turning on bright lights during scheduled darkness.
- Taking away uneaten food when the hermit crabs are still eating.
You may hear chirping when hermit crabs want to be left alone.
Requesting Assistance
Hermit crabs that live together will usually cooperate and assist each other. Alas, some crustaceans are opportunistic, seeing a struggling hermit crab as weak and making a play for its shell.
Is one of the hermit crabs trapped on its back? Hermit crabs can usually flip themselves over, but they may struggle. If so, it’ll need your assistance to right itself.
Hermit crabs don’t always stridulate by choice. Look for warning signs that a hermit crab is trapped inside its shell. The legs will scratch and scrape constantly if a shell is too tight or trapped by dried paint.
Under no circumstances should you pull the hermit crab from its shell. It’ll resist, so you’ll end up tugging off its limbs. Instead, guide it into a water bowl to submerge and moisten the interior.
