What is this? (nature question with photo)

[PippaXo]

Saw this on my walk today. It's a sort of bag that looks like it has been made of gossamer. It has lots of black caterpillars on the outside of the bag and the bag appears to have caterpillars inside too.
The bag has been constructed on a hawthorn hedge.
What caterpillars are these and what is the bag for?

I think it's a type of moth; those are it's caterpillars, the bag thing is the cocoon they were kept safe in until they hatched, I would think!

What a fantastic photo.

Wow, lucky you!

Might be the Hawthorne moth (common in south of UK but not typically found north of Yorkshire), but there are various other moths that feed communally in a silk web. They usually devour a lot of the leaves and can wreck whole hedges. The ermine moth is pretty creepy because they can cover whole hedges with webs, making them look like some sort of Halloween decoration.

Aah thank you! Only taken with ancient android phone!

Thank you for this information! I will go and Google Hawthorn Moths!
We are in Shropshire by the way!

There are quite a few wildlife photography competitions. Seriously, I’d enter it.

Thanks for this. I live in the south east.
The other day I drove past a tree and it looked like it had been completely sprayed with cobwebs for Halloween.

I’ve been wondering what it was as I’ve not seen it before.

Thank you so much!

It looks like a Lackey moth / tent caterpillar nest to me

No idea but it’s a very cool find

Thank you! I think that from looking on Google, they could also be Brown Tail moths. From the pictures of the Lackey moth on Google, Lackey moths appear more orange in colour than the caterpillars I saw.