[Intro]   Lunch is the best time of day, right? Well - sometimes, anyway. But even if lunch turns out to be nasty, like a banana and ketchup sandwich, if we're really hungry - we'll eat it!   That's because we're living things, and all living things need to eat. Or, really, need to eat to get energy in order to survive. But tigers and humans are both living things, and you don't tend to see tigers hanging out at the salad bar - so what's the deal? How do different types of living things get energy?   Well, everything starts with the sun. We may slather on the sunblock and pull out the shades when things get too bright - but plants don't! Instead, they do something only a few kinds of living things can do. They catch energy that comes from the sun's rays and they change it into chemical energy. Specifically, a kind of sugar. Then, other living things, like humans, eat the plants and use that sugar as energy in their own bodies. It's like swallowing sunshine! But much tastier. And more filling.   Scientists classify, or group, animals based on how they get energy. Some living things get energy by eating mostly plants, or parts of plants like fruits or seeds. These animals, like deer and cows, are called herbivores, even though they all kinds of plants, not just the herbs that go in pizza sauce.    But, if you're looking for an animal to split a burger or carne asada taco with, you'll wanna call tigers, hawks, or other carnivores - animals that eat mostly meats -- while humans, bears, raccoons, and other animals whose diets include both plants and animals, are called omnivores. Now you can come up with a really simple model to see how these groups of living things fit together based on how they get energy.   Say we're out for a walk -- there's sun shining on the apple tree, a raccoon hiding in the tree's branches, some insects munching on the tree's leaves, and a hawk circling over a field nearby. How can you arrange these things in a way that shows how they get energy?   Well, first we know that the apple tree doesn't really eat anything. It's a plant, so it can take the sun's energy shining on its leaves, plus some air and water, and make sugar. So what about the animals in this scene? Since the insects are making a salad out of the tree's leaves, it's safe to guess that they're herbivores - plant-eaters. The raccoon would be happy eating either the apples from the tree or the insects. Since it eats both plants and other animals - it's the omnivore in this situation. If the raccoon leaves the safety of the tree, it might get picked off by that hawk - a meat-loving carnivore.   So as you can see, all living things get energy that starts off with the sun. Plants take this energy and change it into chemical energy. Some animals, herbivores, get their energy by eating mostly plants, while others, the carnivores, get it by eating mostly meat. And omnivores, like humans, get their energy by eating both plants and animals.   Now, if you'll excuse me, it's time for this omnivore's lunch!