Aliens in my garden

Any idea what these are? I found them scattered haphazardly all over the leaves of plants in my 12x12 foot garden after we had roughly an inch and a half of rain since yesterday. I think I would've noticed them if they'd been there yesterday or the day before. They're roughly 1/4-1/3 of an inch across, and consist of a very firm gelatinous material around a crisp dark "grain" in the middle, and that has white on the inside of it when broken. No noticeable smell. Slimey (takes awhile to get the inside part out of the goo ball). They were all over pumpkin leaves, basil leaves, grass leaves, pepper leaves, etc...

I know I have a couple small frogs living in a bucket of water, and I know there are snakes, worms and grasshoppers. There's also plenty of birds (bluejays, gold finches, and black capped chickadees are real common right now). Could they be some sort of amphibian's egg (and why scattered all over, exposed?)? The swollen outer coating of seeds dropped by the birds? Alien eggs?



They look like eyes peeking up out of the leaves! They're not attached to the plants - they slide around real easy.



Tucker's not sure what to think - but he's asking too!


(ok, this picture has nothing to do with the above ones - I did take it at the same time, but he was just meowing at me as I took his picture)