The egg sac belongs to a ground spider. It appears when someone collected some of these they decided to try and hatch them. The small spiders that come out of these sacs are blue. The name of the spider this egg sac belongs to is called Zelotes. Here is some information on this from a bug guide and how the person hatched the eggs and what the spiders looks like when they are hatched. Not sure I would hatch this egg sac and have all those spiders living in my yard. They are ground spiders so maybe there are there to eat the red ants in the garden to keep your yard clean. Not sure on this one.
This looks like - Steatoda Triangulose- better known as Triangulate cobweb spider. This spider loves the indoors, but is also a outdoor spider!
We have some very large spiders in Florida and I've seen large egg sacs but not one quite like this.
Looks like it should have a spider setting on top.
Probably should destroy it as it will most likely have hundreds of babies crawling around if left to hatch.
Sometimes you can post your question and picture to forums and someone who knows their insects usually answers. They usually want to know your location.