Four Things You Didn’t Know About Hermit Crab Personalities

Personality is something we often think about in our interactions with the people around us – he’s so kind, she’s hilarious – but it isn’t often that we think about personality in regards to animals. This is because most animals don’t have personalities, right? Wrong! Research has shown that personalities can be seen in a wide range of animals: birds, fish, octopuses, and even sea anemones have all been shown to exhibit personalities. But what about hermit crabs?

  1. Hermit crabs have personalities!

Despite their small size and relative simplicity, hermit crabs are one such animal that have been repeatedly shown to have a personality. In my independent study I attempted to confirm that a local hermit crab species exhibited personality. Personalities are only said to occur in animals when behaviours are consistent through time and situations. My study found that in these hermit crabs, some were bold while others were shy, and these traits were mostly consistent through time. This supports the idea of personality in these hermit crabs!


Common hermit crab of the Pacific Coast of North America: Pagurus hirsutiusculus.

  1. Boldness is one of the most important personality traits for hermit crabs.

Personality can take a variety of forms in hermit crabs, but one of the most important personality traits is boldness. Boldness has been linked to a wide variety of behaviours such as greater exploration tendencies, shorter responses to being disturbed, and faster investigation of strange objects. These behaviours in turn may be important in determining whether hermit crabs can adapt to changes in their environment.


Hermit Crabs eating one of their less-traditional food items; cantaloupe rind left by beach goers! From Pinterest.

  1. Boldness may be related to ability of hermit crabs to eat food that they have never encountered before.

It has been predicted that bolder hermit crabs may be quicker to investigate new types of foods. This trait could be very important if the types of foods available to hermit crabs change, as they are predicted to in the near future. Therefore, one of the main goals of my independent project was to test whether boldness affected how long it took the crabs to begin eating new types of food. Unfortunately, my study was not able to provide evidence for this relationship, meaning that boldness may affect the ability of hermit crabs to eat strange foods, but for now it remains unknown.


Hermit crab exhibiting the newest in shell fashion. From Huff Post.


  1. Shell quality can affect boldness.

Like in humans, the personality of hermit crabs can be changed by how safe they feel. Hermit crabs are dependent on the shells of snails for protection from the world around them. My study showed that the quality of the hermit crab’s shell was related to the crab’s boldness. When the hermit crabs could fully withdraw into their shell, they were much less bold than if they could not fit in their shell. This result is important as it shows that changes to snail populations can have knock-on effects on the personality of hermit crabs!



Hermit crabs are just one example of the many animals that have personalities. Next time you are out on the beach or in the forest remember this, and see if you can notice any behavioural differences indicating personality in your favourite animals!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s