"sleping in atree may not be safe. In another universe, there are nocturnal predators known as 'owls'. they're small, but for smaller animals, they're not safe in tree or on the ground. the higher you sleep, the more likely a winged predator is to pick you off. once they have you and you're in the air, we can't help you" manus was trying to form another ally "the cave would be safest, 3 sides blocked off, and when faced with mass amounts, they'll be at a bottle neck. plus, aerial predators can't snatch you from above and carry you off"