My cats are absolutely terrified by vacuuming, especially Flip, the long haired black cat. He would have to find refuge under the bed, even just the smell of the vacuum would do it. The other 2 cats, Jackie and Shadow are not a fan of the noisy machine either, though they are not as frightened.
Whenever I vaccum, I will do one room and keep the furry babies in a separate room, so they will not have to face the terrifying noise maker, but that does not stop Flip from flipping out regardless.
In this video, you will see a cat that LOVES her vacuum. As strange as it may seem, the vacuum could be a nifty tool for grooming if you think about it. hmmm. At least she enjoys it.
How do your cat(s) react to a running vacuum?