Do tomatillo's self pollinate?

We have some tomatillo planted in a table top bed. It wasnt doing too well at first but now that we've had some consistent rain and cooler weather they have really taken off. There are all kinds of flowers and "lanterns" on the plants but so far to fruit. Do they self pollinate or do we need to get a brush and do it ourselves?
Also, it sure seems to be spreading out and will soon be flowing over the side and down toward the ground. I'm guessing it's a vine plant and not a bush? I'm not sure on the variety though so I don't have much info to give you guys.

Tomatillos are self-sterile....you have to have at least two plants to get fruit set.

Sir G, Photos would be great to see what you mean by lanterns.  Do you mean lanterns the size of the flowers, or lanterns an inch long?

I bought one as an experiment.  Lots of little yellow flowers!  Then I bought a second when I read they need cross-pollination.  I placed it in a pot next to the plant in the corner of the box.  Both flowered like mad, made baby lanterns like mad, and sprawled like mad.  No fruit. Of course, no bees either. Then I used a tiny hair paint brush and managed to get one fully fertilized fruit.  The lantern grew rounder than an inch, and slowly the fruit started growing inside until it filled the lantern.  Next year I will have the paint brush ready at the beginning of the flowering season.

Yes, they sprawl. It's easier to plant them in an area where they can sprawl than to try to contain the sprawl.  Mine grew up, out and fell over the string cage I sloppily built.  Then the stems turned back up.  They are what they are.  Delicious!

I had great success in staking mine. They grew upright like trees, with robust trunks, and the "branches" only sprouted from several feet off the ground, falling down in small arcs that stayed well above the ground but bent down closer to it as the fruit got heavier.

Another one volunteered in a bed my neighbor was letting me use. It sprawled and looked like a vine from the start. The lanterns are weaving themselves helter-skelter through my nearby tomato plant and along the ground. Will definitely stake them again next year.