The weird and wonderful world of slime moulds

11 January 2021 | Posted in Wildlife
The weird and wonderful world of slime moulds
Dog vomit slime mould © Dawn and James Langiewicz

What's definitely weird, has no brain, yet is remarkably intelligent? It's not a plant, animal or fungi - even though it was thought to be for a long time - it's a slime mould.

Slime moulds begin life as very small, amoeba-like organisms and these go on the hunt for bacteria to eat. These can move like giant amoeba, and they ooze their way along woodlands. The way that they feed is by engulfing bacteria and organic matter, so they actually do an important job of clearing up woodland. Usually they go unnoticed until they produce a fruiting body, and this can be very colourful.

More about slime moulds from Wildlife Watch

False puffball or cauliflower slime mould

Did you know that young slime moulds can actually move around in search of food? This is one big difference between them and mushrooms. To be fair, a young false puffball is difficult to tell apart from a puffball (mushroom). If you return to the same spot a day later and it has changed shape, it’s probably a slime mould.

False Puffball (c) James & Dawn Langiewicz

© Dawn and James Langiewicz

Scrambled egg slime

Scrambled egg slime (c) Derek Parker

© Derek Parker

Toxic metals can be poisonous to many living things, but the scrambled egg slime uses its special powers (the yellow pigment that gives it its colour) to make the metals harmless. Look out for this magic slime in your garden this summer after heavy rain. It loves to grow on the wood chips that are often put around plants.

Many-headed slime mould

9. Many Headed Slime Mold.jpg (c) Allen Norcross

© Allen Norcross

Although it doesn’t have a brain, the ‘many-headed’ slime mould is a great puzzle-solver. When two meals are on offer, this amazing slime mould finds the shortest route between them. If it is offered more than two options, it sets up a network – a bit like the London underground system – so that it can move around the different feeding spots as quickly as possible.

Dog sick slime mould

Fuligo septica aka Dog Vomit Slime Mould RSPB PulboroughBrooks 17September2015

© Dawn and James Langiewicz

Discovered suspicious white stuff that looks like dog sick in your back garden, but not got a dog? Well it could be the dog sick slime mould! It can turn up on grass overnight and is most common in September. It doesn’t stick around though. After one night it will turn black, and it will have disappeared in a couple of days, especially if it rains.

Wolf's Milk

Wolfs milk (c) James & Dawn Langiewicz

© Dawn and James Langiewicz

These tiny blobs can be found on dead wood all year round. They can range in colour, from pinky-grey to greenish-black. If you pop one with a small stick, it’ll ooze a brightly coloured toothpaste-like liquid. You don’t want to put this on your teeth though!

Egg-shell slime mould

Found on twigs and sometimes even pine needles, egg-shell slime moulds can look like miniature bunches of grapes. Give them a couple of days and you’ll see why they get their name. They explode. This releases their spores, which means they can multiply. After this, they look like cracked eggs.

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© Ken


  • Annita Mossop:

    14 Jan 2021 12:44:00

    A very good friend of mine, Mr David Mitchell (now deceased) was an expert on slime moulds. He lived in Hartfield, Sussex. He was a biology teacher at Imberhorne School for many years. I thought that you would like to know that we had our very own local expert.

    That's very interesting indeed. It would have been lovely to have been able to talk to him about them.
  • Christina:

    14 Jan 2021 13:39:00

    This was fascinating! I have identified two in my garden!!

  • Eve Montgomery:

    14 Jan 2021 13:42:00

    Very interesting. It would have been nice to have been told the up to date scientific names of these organisms as well though.

  • Joan MacGregor:

    14 Jan 2021 13:54:00

    I find slime moulds fascinating and as it’s proved difficult to find detailed information about the species found in the UK this article was very interesting – and a shame that Annita’s friend is no longer here to provide more details. Is there a slime mould study group in Sussex?

  • Stephen Walker:

    14 Jan 2021 14:19:00

    There’s some fascinating info on the problem-solving behaviours of slime moulds in the introduction to Merlin Sheldrake’s vision-changing book on fungi entitled “Entangled Life”.

  • Julie Allen:

    14 Jan 2021 15:07:00

    Very interesting, I had not heard of some of these. A wonderful insight.

    Many thanks.

  • M. Boztas:

    14 Jan 2021 17:39:00

    Just for info: I never had slime mould in my garden until I applied coffee grounds, mixed directly into soil..Slime mould appeared in areas where I applied the coffee ground liberally! spreading very fast in a dendritic fashion at night

  • Julia Brock:

    15 Jan 2021 20:58:00

    This weekend – I go looking !

  • Susanne Wolf:

    16 Jan 2021 11:57:00

    Great info and fantastic pictures, just would like to know the actual size of these creatures.

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