Where we live there are a lot of these. They are cockleburs, which grow on a weed. Very interesting seed pods that are usually about 3/4 to 1 inch long.
When they mature they attach themselves to anything they come in contact with, like velcro. It can take hours to remove them from a horse's mane and tail once they become entangled and there can sometimes be dozens on one animal. I hated getting them on my socks. But I guess this is just another of nature's way to disperse seeds.
My Nana would call those cockleburs, 'hedgehog eggs'. Wouldn't it be funny if they were?