Bees
Called Colony Collapse Disorder Bee Colony Collapse happens when most of the bees in a hive disappear. The reasons for this are many, as they are with most crises. Stress is a factor. The bees are trucked to work a crop. There is often no ground cover or shade for them near the crop, and also little water. Pesticides called Neonicotinoids are used on crops which are harmful to bees. Neonicotinoids are being used less and less. You can avoid buying and using Neonicotinoids. List. Also, don’t buy plants from Nurseries which use them, which means get to know your nursery. Find an organic one if you can.
Varroa mites also cause this disorder. The mite acts like a tick. Disease is spread by the mite which weakens and can kill the bees. Even if the bees aren’t killed they are less able to handle stress and winters. To combat Varroa mites, grow mushrooms. Bees get nourishment from the mushrooms which kills the mites.
You can start your own hives. If you want to start on a small scale, consider Mason Bees. Mason Bees are rather small.
This video shows how to build a Mason Bee hive. It can be as simple as drilling holes in a piece of wood – of course you want the right size holes.
Or perhaps you want to try to raise bees in jar.
There are other pollinators besides bees. You can put up a bat house or plant a butterfly garden (butterflies do not do well if any pesticides are used).