One of the unusual behaviors you may notice in your parakeet is puffing and posturing. They puff up for various reasons. The foremost of these reasons is body temperature regulation.
When parakeets are cold, they will puff up to conserve their body heat. If you pay attention, you may notice that your parakeet puffs up more commonly during cold winter days.
Interestingly, your parakeet may be puffing its feathers to show off and get some attention. It may be showing off to you, a visitor, and if it is a male, it may be showing off to a female bird.
Your parakeet may also puff its feathers up while trying to clean itself. The puffing process helps to shake its plumage a bit and shake off debris and dirt.
Sometimes, the feathers of a parakeet may get crooked. When this happens, they may get uncomfortable. But they will also try to remedy the discomfort, and one way they do this is to puff and ruffle their feathers.