This is the skin-crawling moment a camper woke up to hundreds of spiders gathered on a tent.

The holidaymaker witnessed clusters of daddy longlegs scrabbling across the shelter at Lake Clark National Park and Preserve in Alaska.

Footage shows the arachnids scattered and pressed against the mesh, creating an eerie scene.

Experts said the phenomenon is known as aggregation, but the behaviour among daddy longlegs still remains unknown.

However, scientists suggest that the clusters may help in mating, humidity regulation, or protection from predators.

This occurs more frequently in autumn, when dry weather and shorter days increase the risk of dehydration. By clustering together, the spiders help maintain a humid environment crucial for their survival.

Daddy longlegs, also known as cellar spiders from the Pholcidae family, have a mild venom but it does not pose a threat to humans.