Many insects and other arthropods eat bees outright, including spiders, assassin bugs, and robber flies. Others are parasitoids (that is, as larvae, they are parasites that end up killing their hosts), including certain types of flies, wasps, and beetles. Ants may raid the nests of bees.
Many types of birds eat bees, and many other vertebrate insectivores aren't put off by the idea of a little sting, either.
Many types of insects have evolved with colors and patterns that resemble the black, yellow, and orange of stinging bees. These insects, especially many types of harmless flower flies, bee flies, and moths, make potential predators hesitate or back off before they attack. Some species of predatory robber flies are extremely convincing bumblebee mimics.
Native bees play a critical role in the health and integrity of our natural habitats. Amid Missouri's array of woodlands, grasslands, and wetlands is a wide variety of wildflowers and other flowering plants. Most of these are pollinated by various types of bees. Without pollination, they cannot produce seeds; they would not reproduce. The seeds, fruits, and the plants themselves are the food of countless animals. For example, what would goldfinches do, if there were no sunflower, coneflower, or thistle seeds to eat, and no thistle down to line their nests with? In a very real way, pollination is critical to life as we know it.