Some kind of insect nest?

Some kind of insect nest?

Observation - Some kind of insect nest?. Description: Please could someone tell me what this is? The texture appeared to be papery so I thought maybe it's some kind of insect nest? It was about 5 cm and was found inside my mum's compost bin. She has removed the plastic lid and replaced it with an old mat

Please could someone tell me what this is? The texture appeared to be papery so I thought maybe it's some kind of insect nest? It was about 5 cm and was found inside my mum's compost bin. She has removed the plastic lid and replaced it with an old mat because there are blackbirds nesting nearby so it's less noisy for them (and quicker when she needs to use the compost bin). Anyway, this object was actually found attached to the underside of the makeshift mat lid.