You can do this relatively easily with custom movements. Create a target object that is re-positioned randomly every few seconds within whatever space you want. Then set your bee object to have custom movement, and every tick accelerate towards the target. You may need to set a maximum speed for it, too. It'll give it a nice, smooth motion if you get your values right. Player around with it and see what works.
You could create an invisible base object that follows a smooth path, then attach the bee on top of it that would have the random flying animation for it. So it would smoothly follow the player or whatever, but still appear to be flying erratically.