Hermit crabs can see, but not in the same way humans can see.
Can Hermit Crabs See?
With two eyes on eyestalks that protrude from their head, they have an expansive field of vision. Their eyes have a compound lens, common with most crabs and insects, which is a complex system of independent photoreceptors.
This vision system allows them to “see” many more images per second through a complex system of independent lenses, in addition to having a much wider view of everything around them.
Hermit Crabs have an expansive field of vision
But Can Hermit Crabs recognize their owner?
Since it’s very clear that hermit crabs can see, and have strong eyesight (though different than how we see as humans), the common question hermit crab pet owners have is if their hermit crabs can recognize them.
Hermit crabs most likely can not recognize a human face with their eyesight alone. However, it may be possible for hermit crabs to learn to recognize the hand that feeds them (literally) through a combination of vision with their other sensory organs and receptors.
Since every human has a distinct scent, it is very possible that hermit crabs can learn to recognize the size of the hand entering their home plus that distinct scent, and possibly the movements of that hand.
More importantly than your hermit crabs recognizing you, is feeling comfortable with you. They should know that you are not a predator and mean no harm.
You are gentle and hand them snacks they love, give them clean water and keep their habitat clean and fun. This connection gets created over time, as they experience only positivity every time that big hand comes into their home.
Scenario #1:
Jordan is an adult who’s had his hermit crabs for many years. He is the only one that feeds, cleans and cares for these hermit crabs.
He is always careful to move his hands slowly while inside the habitat.
The size of his hand does not change, his scent remains the same, and his movements are generally always the same.
His hermit crabs have learned to recognize him, and they feel comfortable with him and know he’s not a danger.
Scenario #2:
Jessie and Sara are 10 year old twins who just adopted a few hermit crabs. They love playing with them, and their hands are often inside the habitat.
Their parents also make sure to change the water in the habitat daily, and clean things as needed.
There are lots of hands that enter the habitat, all different sizes, scents and movements, so these hermit crabs probably won’t learn to recognize these humans.
As long as care is taken when handling these hermit crabs, most likely these pets will learn to feel comfortable with humans.
How Hermit Crabs Interpret what their eyes see
Their 2 pairs of antennae (4 total) near to their eyes, help them make sense of what they see through their eyes.
The long pair of antennae provide touch and feel, while the shorter bent pair (often orange at the tips) provide taste and smell.
These sensory receptors help hermit crabs interpret the visual images they receive from their compound lens eyes.
Also very important to the system are the setae, those thousands of tiny “hairs” on their legs.
Their setae help them “sense” things around them like vibration and sudden changes in air flow that could indication an approaching predator.
Thousands of Setae Aren't "Hairs"
Setae are also used for “drinking” and in the mating process as well.
These “hairs”, which aren’t hairs at all, are a crucial part of their sensory system and work with their vision to help interpret their environment, find food and water, avoid danger and find appropriate extra shells.
If you observe a sleeping hermit crab who will most often be resting with his shell covering just his eyes (see my post on “Do Hermit Crabs Sleep” here), if he feels something (or someone) approaching, he’ll raise a leg.
He’s not using his eyesight at this point, he’s using the setae on his leg to feel the change in air pressure around him.
Is it something very large? Is it something very small?
If he senses something fast moving that could be a predator, he’ll wake up and move. If it’s the slow moving hand that he recognizes and is comfortable with, he’ll most likely continue sleeping.
So while hermit crabs don’t “see” like us humans, they do have an extraordinary ability to view the world around them in a very complex and efficient way. Just don’t expect them to recognize your face!
Last update on 2024-04-27 / Affiliate links / Images from Amazon Product Advertising API