Yesterday my parents discovered these 'things' attached to the varnished wooden fascia board outside the downstairs bathroom. They are attached to the outside of the house, in a sheltered spot. They live in Somerset, UK.

They are approximately 6 cm in length/diameter (some are round and some not - see photos), and have been there for about a week (it is about a week since this part of the house was looked at).

My questions are: 1) What are they? Mould? Fungus? Insect? 2) Is it damaging the wood, and therefore should it be removed?

One of the non-circular 'things' with a tape measure for scale

Side view - to show how they are attached

Circular 'thing'

  • 1
    It sort of looks like wolf's milk slime mold, but they're usually much smaller than your photos.
    – Matthew
    Apr 12, 2020 at 15:01
  • 1
    My first thought was an insect casing or cocoon, like leaf scale, but these things are huge! I have installed Google Lens on my phone and it is pretty handy on identifying items, I would try that.
    – Jack
    Apr 12, 2020 at 15:13
  • What is your location?, I haven’t seen anything quite like that in the Pacific Northwest, but I agree it looks like a growth or some kind of critter. Looking at the wolf’s milk I don’t see the area around the base but did see some that were single with no scale that looked similar. My wife has that app on her phone it may identify it it is cool.++
    – Ed Beal
    Apr 12, 2020 at 16:46
  • I have added the location - we're in the UK, not the USA. I agree; it looks like wolf's milk, but I don't know if it can grow that big. I'll definitely try out Google Lens - good idea.
    – Tempest16
    Apr 12, 2020 at 16:49
  • 1
    I'm married to a naturalist. She suggests cutting one open. She thinks it looks like a fungus (which can spring up in that timespan) and its color may be due to blending with the pigments in the paint.
    – Matthew
    Apr 12, 2020 at 19:04

2 Answers 2


My dad removed them this morning, and they are a fungus. A lot of dark spores came out when he pierced one (see photo).

The fungus didn't damage the paintwork, as can be seen in the photos; it just left a mess of spores behind.

Site of removed fungus, with paintwork damaged

Contents of one of the fungus


They look like some types of spider egg sacs. https://spidermentor.com/2018/01/02/the-egg-sac-gallery/

Usually the spider hangs around, but not always.

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.