Millan's techniques are almost exclusively based on two techniques: Flooding and positive punishment. In flooding, an animal is exposed to a fear (or aggression) evoking stimulus and prevented from leaving the situation, until it stops reacting. To take a human example: arachnophobia would be treated by locking a person into a closet, releasing hundreds of spiders into that closet, and keeping the door shut until the person stops reacting. The person might be cured by that, but also might be severely disturbed and would have gone through an excessive amount of stress. Flooding has therefore always been considered a risky and cruel method of treatment.