@sara--95,
yeah, theres plenty of bacteria in the air. You just need to keep the carbon to nitrogen levels balanced. Whenever I start a compost pile I awlays take a 2 liter soda bottle and fill it with a cup of ammonia, a full beer and top it off with water, then hook this up to a garden hose and wet down the compost. Itll get er cooking and , if you keep a skid underneat to allow air to enter, you will have done compost in 2 weeks. I use it right after it cools down and I start my piles far enough away from the gardens or living spaces so It doesnt look funky in tthe way of the gardens.