wow i say leave it and see what emerges! ;)

I think that's a Preying Mantis egg case.
Lucky! They're Good Guys!

Here's some pics from the internet.

Here is a link that might be useful: Preying Mantis Eggs

wow! that is what it looks like! praying mantis can hang out all summer...Thanks BarbJP!

Praying Mantis. Lucky you!

Linda

If you have hummingbirds, keep the mantis away from the feeders. They kill hummingbirds.

While mantids can eat hummingbirds, I think it probably is not widely common. Although it may be a learned behavior and becoming more frequent in specific regions.The problem is, how do you keep them off of the feeders? The species common to my area fly. They have a good amount of other, presumably easier, prey available though and I have remove only one from a feeder over several decades.

Five or six years ago, I managed to catch one of the egg cases at hatching time. There were so many tiny young emerging it was amazing! But there was also a hoard of waiting ants trying to take down as many as they could overpower. I took photos, but the battles were a bit brutal for publication. Nature can be fascinating to watch though.