Pets respond to diverse ways. Typical physiological reactions are: increased heart rate, tremors, increased breathing rate and sweating (sweat paw prints). It can also be observed that frightened or anxious pets tend to urinate or defecate and empty their anal glands.
Typical behaviors are: avoiding eye contact, lip licking, yawning, scratching and turning away.
More obvious reactions are: hiding, a crouched posture, ears flat on the head, eyes wide open, tucked tail (dog). In general, it is easier to identify anxiety and fear in dogs.
Depends on individual animal and his previous experience The first reaction most people have is trying to avoid the situation.
If this is not possible, the animal will try to escape (flee, hide). If that is not possible either, it will certainly show defensive-aggressive behavior (make itself “bigger”, growl). In extreme situations, the animal freezes, which means that it literally cannot move, as if paralyzed.