To face the problem of subsistence, for instance, most critters—as Donna Haraway describes microbes, plants, animals, humans, and nonhumans—have developed complex solutions and strategies to seize and use energy in conditions of scarcity, without damaging their ecosystem’s balance. Animals, unlike plants, are not able to directly transform solar energy and chemical elements available in their surroundings into nutrition and thus depend on other living beings for nourishment. However, some of them, referred to as “green animals,” have progressively solved the problem of food scarcity in environments where at least the sunlight is abundant. Through symbiotic relationships with plants, they have evolved into plant-animal hybrids that are able to seize and transform solar energy without the perpetual mediation of other living beings: green animals have “learned” to photosynthesize.