
Hermit crabs line up by order of size to exchange shells [video] - PhasmaFelis
https://vimeo.com/117375257
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SpikedCola
Wikipedia calls this a "vacancy chain"

> In a vacancy chain, a new resource unit that arrives into a population is
> taken by the first individual in line, who then leaves his/her old unit
> behind, this old unit is taken by a second individual, leaving his/her old
> unit behind, and so forth

Neat!

[https://en.wikipedia.org/wiki/Vacancy_chain](https://en.wikipedia.org/wiki/Vacancy_chain)

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aric
Hermit crabs are wondrous and hilarious. I had a couple as pets decades ago.
That's before I knew about that industry and how it deprives these creatures
of a beautiful, wild existence. The following is worth considering.

[http://www.peta.org/living/companion-animals/7-reasons-
never...](http://www.peta.org/living/companion-animals/7-reasons-never-buy-
hermit-crab/)

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FrankenPC
Crabsort: O(n)? It's a small set. Although there is a 4 plate/ five customer
contention problem to boot. I can't tell if Crabsort is stable though.

Fortunately, everyone leaves with some spaghetti even if it's not a 100%
optimal solution.

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GeneralMayhem
It should be 5 plates / 4 consumers, were it not for the late-arriving crab
throwing a wrench in at the last minute.

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Buge
Why was there only one shell left for the crab at the end?

There was an extra shell at the very beginning, so at the end it should be
able to choose between 2 shells.

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Kenji
Shellsort :D

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chowyuncat
The Brits really are obsessed with queuing.

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wpeterson
Hermit crabs are great scavengers and mostly peaceful, but they hardly wait
for a shell to be vacant before moving in. They will definitely kill a live
snail to take their shell if they need a bigger home. Or another crab.

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kenrikm
I have a reef tank on my desk at work I get to watch this process happen on a
daily basis. I have to keep adding larger shells to the tank because if I
don't they will kill the snails and steal their shells. If there are enough
shells available they leave the snails alone. Recently one of the medium size
crabs decided to take the a shell that used to belong to a turbo snail, much
too big for him as he can barely drag it around. I've come to the conclusion
this crab is American and is going to fake it until he makes it.

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gcb0
you need a camera there. my old crabs where boring...

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agotterer
Maybe a stupid question... But if each hermit crab grows their first shell and
the sheds it for something larger. Where do the larger shells come from? also
why can't they grow subsequent shells after shedding?

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baddox
The hermit crabs don't grow the shells. They use snail shells.

[http://en.wikipedia.org/wiki/Gastropod_shell](http://en.wikipedia.org/wiki/Gastropod_shell)

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blfr
One of many reasons why everyone wants to be a crab.

[https://en.wikipedia.org/wiki/Carcinisation](https://en.wikipedia.org/wiki/Carcinisation)

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pvaldes
Well, this is not so simple as wikipedia says. Crustaceans are a really big
and wide group of life forms, and Carcinisation can be applied only to some
groups of decapods (about 15.000 extant species). There are also about 11.500
species of Copepoda, 10.000 Isopoda, 13.000 Ostracoda, 9.500 Amphipoda and
1.300 Thecostraca, for instance, and none of these are crabs.

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jonah
I've seen this happening on the beach in Costa Rica. We'd been told about it
and then to happen upon it actually occurring was quite a neat experience.

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SimeVidas
But where are the shells coming from?

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hcarvalhoalves
[https://en.wikipedia.org/wiki/Sea_snail](https://en.wikipedia.org/wiki/Sea_snail)

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Apofis
[https://en.wikipedia.org/wiki/Hermit_crab](https://en.wikipedia.org/wiki/Hermit_crab)

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taivare
Crab's have resolved homelessness , but were still screwing are species over
with sub-prime loans.

