What's inside if you crush one? I too think slow release granules that have been partially dissolved, so they're smaller. As @Fairygirl mentions they're often found in composts.
Billericay - Essex
Knowledge is knowing that a tomato is a fruit. Wisdom is not putting it in a fruit salad.
@MrsPryce, I would definitely collect them and put them safe until they hatch out. That will show you what they are. Just make sure they don’t escape before you identify them. Valerie
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I too think slow release granules that have been partially dissolved, so they're smaller.
As @Fairygirl mentions they're often found in composts.
Billericay - Essex
Knowledge is knowing that a tomato is a fruit.
Wisdom is not putting it in a fruit salad.
Gardening in Central Norfolk on improved gritty moraine over chalk ... free-draining.