Lack of food throughout the year is a leading cause of the world’s decreasing bee populations. This is what they sound like when they are buzzing, or flying, around, looking for food. During some seasons, there just is not enough nutrition in the natural environment to feed all of the bees. Also decreasing are the diversity and numbers of flowering plant species. Reasons include use of pesticide products and development of what once were rural areas. Bees, other insects and even some animals act as pollinators. They cause plants to make fruit or seeds. They do this by moving pollen, the yellow substance produced by plants, from one part of the flower of a plant to another. However, pollen is the only protein that bees eat.