Bugs
Insects can be very noisy and therefore a natural form of noise pollution. From crickets chirping on summer nights to the enormous swarms of Cicada that live around the world, bugs can create a lot of noise. Swarms of other insects, such as bees, wasps, flies and gnats can also create a lot of noise pollution in the world around us. The small sound of each bug magnified as a massive quantity of bugs travel together can create a very big and disturbing noise.
Weather
Constantly changing around us, the weather can be one of the most distressing noise pollutants. Sometimes present only for a short while -- here quickly and then gone again, extreme weather can have serious effects. High winds and storms can block out all other noise and cause fear in those experiencing the storm, even if there is no threat. Thunder and lighting are a good example of this, as children and pets will commonly run and hide when they hear loud claps of thunder or see flashes of lightning.
Birds
Birds are naturally noisy creatures, singing and chirping everywhere all the time, except during times of the year when they migrate to cooler or warmer climates. Birds can create quite stressful situations for nearby dwellers due to excessive noise. Some exotic pet birds like macaws and cockatoos make noises that have been compared to human screams: In 2011, film director Quentin Tarantino sued his neighbor, TV writer/producer Alan Ball, because the racket made by Ball's exotic birds was disrupting his ability to work.
Pets and Animals
Most noise complaints in neighborhoods are filed due to the noise caused by the pets, particularly dogs that bark excessively when their owners are not around. Although pet noise is considered an urban or suburban problem, rural areas have their equivalent: The pets and animals that live on nearby farms can moo, bark, squeal, squawk, quack and wail. These noises combined can certainly create noise pollution, just as several dogs or a few alley cats can.