Short squeezes are extremely rare in penny stocks. Usually when they do occur, it's because a small group of insiders controls the stock's float, and manipulates a squeeze by promoting the stock to create demand, and then cutting off the supply of stock to the market, squeezing any MMs who sold naked into that demand.
CYNK is perhaps the best, and best-known, example. Most of the people behind the manipulation scheme are now behind bars.