How many nights are in Animal Hospital Anomaly?

Animal Hospital Anomaly features 10 nights of increasing difficulty. Nights 1-2 are tutorial phases where you learn the basics and encounter weaker anomalies. Nights 3-4 introduce more dangerous entities like the Distorted Patient and Echo Child. Nights 5-6 are when The Doctor becomes active — this is a major difficulty spike. Nights 7-8 feature multiple anomalies patrolling simultaneously, requiring strong teamwork. Nights 9-10 are the ultimate challenge where nearly every anomaly can appear at once. Surviving all 10 nights unlocks the game's ending and associated achievements.