cocoon like things near hay box

[AidaB]

Hi!
I have spent my morning dismantling the piggies playpen(c&c), lifting all waterproof and fleece layers, and giving the whole floor etc a good clean.

I found some cocoon like things mostly near a box of hay, when squished they let out a white puss. They are about half a poo size. they don't photograph well, just look like a guinea pig poo in a photo!
I have had a little search but not coming up with anything that looks similar.
Any ideas welcome.
Big box of hay currently moved away from our Guinea pigs, I would hate to have to throw it out. I treated them to Hay box hay, which is a rare occurrence for us.

 

[Eriathwen]

Do they look like the pictures below? If so they're fly pupae, I'd have a look for anywhere warm, dark and damp that may have encouraged them to lay eggs as there may still be some maggots (their life cycle is extremely quick though)

 

[AidaB]

Thank you. Think you may be right. Look very similar. High chance coming from the chimney, flies randomly appear from the chimney in the summer.

 

[Bill & Ted]

Great you noticed them! We had a plaque of caterpillars once that came from the hay. Harmless but not very nice climbing up the walls

 

[AidaB]

Soooo…. Clearly didn’t get them all, spent the evening chasing flies .
Boys are alternating between intrigued and not impressed!
Other boy balancing, trying to chase a fly on the ceiling, with spectators.

 

[Free Ranger]

My friend had this in her kitchen and it turned out she'd had a bird drop down the chimney and die (or die and drop down the chimney - we don't know which) so the only not-very-useful suggestion I have is chimney pot toppers which will at least prevent it happening again. We had to get them on ours because a wood pigeon came down (twice) and made a right mess in the bedroom!

 

[weepweeps]

Gorgeous little piggies watching. Making sure daddy slave gets them all .