It's like something from a 1970s B movie - so have creatures from another planet overnight enveloped parts of a Norfolk housing estate in their wispy cocoon? In fact, the translucent web that has taken over bushes on Thetford's Abbey Estate was created by moth pupae more at home in hedgerows in the countryside.

It's like something from a 1970s B movie - so have creatures from another planet overnight enveloped parts of a Norfolk housing estate in their wispy cocoon?

In fact, the translucent web that has taken over bushes on Thetford's Abbey Estate was created by moth pupae more at home in hedgerows in the countryside.

Since they appeared almost overnight in Chester Way early this week, they have proved to be something of a talking point.

But, despite initial fears they could be an infestation of spiders, they have been found to be the pupae of a harmless type of Ermine moth by Breckland Council.

The only damage they will cause is to the bushes as the caterpillar-like pupae strip them of vegetation, munching their way to becoming fully fledged moths.

Gilbert Addison, countryside officer at Breckland, said: “It's Dr Who comes to the Abbey Estate.

“Some of the locals were worried it was spiders, but no one has wanted us to turn the flame on them; they are completely harmless.

“Although the gut reaction is to go into Starship Trooper mode, there is an alternative - to celebrate such a wildlife spectacular and explain to people they are not being overtaken by Dr Who spiders.”

A sign has been put up to explain to local residents what the startling webs are.

Moth expert Les Hill, from the Dorset-based Buttery Conservation Trust, said the larvae would have been in the bushes since about September last year after first being laid as eggs by adult moths in August.

They spend winter in the bark and foliage of the bushes before waking up in spring to spin their cocoon-like web to protect themselves as they pupate and then munch their way “gregariously” through foliage on the bushes.

Once they've had enough to eat,

they pupate in about June or July and live as moths for about just two months.