Thirteen Eko AI agents turned a virtual island into their own playground

MIT CSAIL researchers placed 13 independent copies of an AI agent named Eko on a simulated desert island for 30 hours each with no task, score or reward. Running on Claude Opus 4.7, the agents built structures, invented games and discovered an unanticipated block-tossing trick, then outperformed fresh copies on later challenges.

• 13 Eko agents ran for 30 hours each with no goal or reward
• Experienced Ekos averaged 10.3 objects on the Spire vs 3.5 for new agents
• Six agents independently found a mid-air momentum-transfer trick
• Erasing one line of an agent's notes removed its learned skill