They don't start out quite that large. But, like yeast dough, they grow in size as they are subjected to a little bit of the spring sun's warmth.
Particularly in my settlement/silt ponds, I'm again seeing all kinds of life that looks like it came from an alien planet. Frogs, toads, salamanders, newts ....
It is all fun, and they will add to spring and summer serenades, which thankfully get repeated year after year.