Answer: Caterpillars are the larvae of either moths or butterflies. Generally the adult lays eggs on what she deems a suitable source of food for her offspring. As the eggs hatch, the larvae feed on the host plant and then pupate, become adults and fly away. I don't know what your fuzzy white caterpillars are, but they must be eating something nearby or they've dropped off a tree and onto your bushes. As long as they are not feasting on your plants, I'd leave them alone. Just out of curiosity, why not put a couple of them into a container and take them to your local extension office or Master Gardener Clinic? They should be able to identify them for you and then you'll know what you're dealing with.
Best wishes with your garden!
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