A mother has spoken of her shock after spotting this eerie sight of web-covered railings and bushes near her local garden.
Arachnophobe Sarah Longfellow, 34, was greeted with metres of spooky giant cobwebs which completely covered trees and bushes overnight in Castleford, West Yorkshire.
She initially thought the railings and bushes had been vandalised with silly string or fake snow, but a closer inspection revealed it was actually silken nests for thousands of insects.
There were so many tiny creatures that she almost swallowed one as she approached.
Longfellow said she was "creeped out" by the cobwebs, which had completely covered an entire tree and bushes overnight.
She said: "When we went up to it, it just looked like Halloween had come early, but then I noticed the webs were real.
"At first, I thought it was going to be spiders, which I'm terrified of, but my son loves. However, as we got closer, it turned out to be caterpillars inside and underneath the webs, and it then became more fascinating to me.
The mother-of-one said: "I was panicking a bit when one accidentally went in my mouth, and I did worry I might have a reaction. I didn't know what was going to happen.
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"But when I looked online, it said they were not poisonous and were harmless to humans."
Longfellow, a council technical support office from West Yorkshire said she first spotted the mass of webs last week, while driving with her 3-year-old son Cain.
She said: "The first time I saw them, I was driving past. We were on our way to a party, and I thought somebody had sprayed silly string on some bushes - it looked just like snow.
"On the way back, I stopped as I thought it was a bit strange, and then I thought it was going to be a load of spiders.
"But I was happy that they turned out to be caterpillars, and my son liked them too, as he loves The Hungry Caterpillar book.
By last week the insects - Ermine moths - had completely taken over the trees, plants and railings of one side of Lock Lane community garden in Castleford.
The moths which eventually appear from cocoons spun by the caterpillars are white or grey with black dots and look similar to ermine fur clothing, hence their species name.
Dr Chris Terrell Nield is principal lecturer in Ecology at Nottingham Trent University. He told Yahoo News UK: "While it is not uncommon to see these webs over trees and bushes, they often go unnoticed. An army of this size is certainly very unusual.
"The adult moths will have laid their eggs on the trees and bushes, then the larvae hatch and start spinning webs to protect themselves from predators, such as birds.
"In this instance there must have been thousands of caterpillars and such a concentration will do the tree damage and affect its foliage, but they pose no risk to humans. And once the moths are hatched they really are very spectacular, they are beautiful."
"The caterpillars were all underneath the webs," said Longfellow. "It was so extraordinary - and they had covered a number of bushes as well. I have never seen anything like that. They were hanging down from the trees and blowing in the wind."
"Apparently, they create these webs to protect themselves from birds. They strip all the leaves and have cocoons, and then later turn into moths."
The silken webs hold thousands of caterpillars, usually emerge in May or June then slowly disappear over the summer allowing bushes and trees to recover.