Do budgies experience anger? Aggression I can understand - they tend to go all 'thin' ie feathers not fluffed up, wings appear defined at the 'shoulder', not resting fluffily on their fluffy little bodies, and they tend to make 'ak! ak! ak!' tweets quite rapid and high pitched repetion. In this, it is not much different from their fear or anxiety reaction. Given the fleeting emotions of budgies they probably can't tell much difference either. A budgie feeling aggression will then go on to peck at or bite the object of the aggression, usually another budgie. A budgie experiencing fear will back off and if unable to fly away will bite anything that gets too near, ie my thumb.