What kind of defense did mammals have against dinosaurs?

Mammals during the time of dinosaurs primarily relied on small size, agility, and nocturnal behavior as their main defenses. Many were small enough to evade predation by hiding in burrows or crevices. Additionally, some developed adaptations like enhanced sensory capabilities to detect predators, while others may have used social behaviors to avoid detection. Overall, their survival strategies focused on avoidance rather than direct confrontation.