Hi Mgmg and welcome to GoY. Any chance of a photo of the grey/silver balls?

depends on how big? could be frog spawn, snail eggs etc
a photo or at least size would be useful.

One is unlikely to see frog or toad spawn on terra firma. There are three possibilities. First it could be a type of mushroom called "puffball". Second it could be a clump of land snail eggs. These eggs though not the same color have the appearance of a little clump of caviar as found on a canapé. The third possibility is that it could be some type of fecal droppings from an animal.

I did see lots of isolated dolps of spawn when a crow had been using frogs for food. when stabbed the spawn was ejected and unfertilized it had a whitish/grey nucleus. rare but not un common.
that's why I wondered what size it was :o)

It won't be puffballs here at this time of year. A photo would help.