physiological needs

What have the boys done to take care of their physiological needs? (cahpter 1 and 2)

Some parts of the physiological needs are already given: O2 and water. There is a lagoon with none salt water so they can actually drink the water. There are pigs, animals to hunt on the island and they've also find fruit. One of the first things they set up was a hunting group, so they get food, meat. But when they saw the pig which was caught in a bush, Jack ( but everybody understood why he couldn't, so they couldn’t have either) couldn't kill the pig at once. Jack hesitated and the pig ran away. So they don't have food; just some fruits the little children found on their way to the top of the mountain.