I don't think those are seeds, more like eggs from something.

Where are you finding them? in soil, on the surface of compost? How big are they? I'm intrigued. Lichens don't produce seeds as such. and fungal spores are usually much smaller.

They are small and on soil surface, path, everywhere

I thought of Corydalis seeds but it is too late for them and they would need a host plant nearby. Try squeezing them, A777, and see if the are hard or if they burst. Seeds will be hard and eggs will squash.

Space invaders??

lol Stera!

Identical to the seeds I've recently obtained from Chionadoxa, - ring a bell Bulbaholic? :-)

Except chionadoxa seed doesn't spread around all over the place... very odd!

Chionadoxa stems and seed heads fall over onto the ground, so I would have thought that the source would be pretty obvious. They do look rather similar, though, Sophie.

I think you may be right about them being Chionadoxa seeds as there are lots and lots of them in that part of the garden but maybe I haven't noticed the seeds before. Time will tell. Thanks for the replies all of you!