Choose two nonhuman species that interact with each other, such as bees and flowers, or predator and prey species, or two species that compete. Or, you can consider the effect of an environmental factor on living nonhuman organisms, such as the effects of light or sound on plants or animals, or how food preference, or nutrient quantity/quality affect plants or animals. These are just a few examples. Your observations may lead you to many other types of questions about living organisms, their interactions, and requirements for life.