A defense mechanism is a way our mind protects us from emotional or psychological discomfort. It's like a mental shield that we use unconsciously to cope with stressful or challenging situations. Full definition
Cats and dogs may view the bird as prey, in which case you'll want your bird to use its natural defense mechanism of flight to escape harm. (thesprucepets.com)
It is a natural defense mechanism against natural change. (climatism.blog)
This is a natural defense mechanism as your body wants to get your blood sugar back up into the normal range as quickly as possible! (hardgainermusclebuilding.com)