I'd say Dig It, and see what you get. (I'm one of those what-the-heck type of gardeners.)

If you look at the fresh garlic bulbs in the grocery store, you can see what to expect. It should have several sections (cloves) and be wrapped in thin white or reddish papery layers.

There is a 'wild' garlic that's an independent grower, and that might be what you have. I've never had a problem with it, so can't tell you how hard it is to get rid of.

I moved into a house with wild garlic growing rampantly through one of my flower beds. It has a pretty flower and is supposed to keep the rabbits at bay (which may be why it had been planted in the first place.) I would say absolutely it is rather invasive. Mine has bulbs that look like tulip bulbs. I dig some of it out, but leave some of it to deter rabbits.