This is the heartbreaking moment a hermit crab took refuge inside a broken piece of glass bottle in Thailand as natural shells are in shortage.

Passer-by Tum Chutipong found the tiny crustacean while walking along a beach in Krabi province on November 3.

Tum, who works for the Mu Ko Lanta national park, said he was saddened after seeing that the red-coloured crab was struggling to move about in its heavy glass home while looking for food.

He said: "The poor crab looked so pitiful. It had to find non-natural things to live.

"It may have run out of available shells to climb inside and settled for the broke bottle instead."

The tiny creature is one of the tens of thousands of hermit crabs migrating into beaches in the province to mate and exchange their outgrown shells.

However, natural shells in most of the islands are at a shortage which experts believe are mainly caused by irresponsible tourism.

Tourists have been blamed for collecting brightly-coloured shells and taking them home as souvenirs, resulting in a shortage on the island.

To address the shortage, the national park now urged the locals and tourists to donate unused cone-shaped shells they gathered from the beach to their office.

About 200kg of shells have been sent to the park so far which they plan to distribute on December 5, during the special Thai father's day event.

Hermit crabs come to the province in a great migration to mate and look for bigger shells to transfer their exoskeletons.

When the shells available are limited, they can occupy empty plastic bottles, baskets, and bags as little homes.