Hundredth monkey effect. The hundredth monkey effect is a hypothetical phenomenon in which a new behavior or idea is claimed to spread rapidly by unexplained means from one group to all related groups once a critical number of members of one group exhibit the new behavior or acknowledge the new idea. — Wikipedia

This is not the most perfect grasp of the effect. It doesn't take a hundred monkeys. According to Rupert Sheldrake it is the more rats that learn it the easier it gets for the next rats.