Probably because they are considered to be pets of witches and other evil sorcerers. A bat's fur and a black cat's are both dark in colour and vampires are considered to like dark things. Also bats and some cats come out at night and so do vampires. There is such thing as a vampire bat and quite a lot of cat's bite their owners so that is also something they have in common.
Most animals (such as bats, cats [usually black cats], wolves, spiders, rats, crows and ravens, etc.) are associated with Halloween because they are either nocturnal, dark in color and therefore associated with death, or associated with legends and monsters (bats = vampires, black cats = the familiars of witches or even witches themselves, wolves = werewolves, and spiders are just plain creepy. Also, crows and ravens are associated with death.)
Rats and cats (all cats, not just black ones) are "related" to vampire bats very distantly, in a cladistic sense.
Vampires can turn into wolves, mist, fog, cats, and bats.
cats, bats, wolves, rats, mist.
There are a few animals associated with Halloween. Three common ones are bats, black cats, and spiders.
Through vampires. Vampire bats are known to suck blood off of cows so people thought they were vampires in disguise. Since vampires turn into bats and vampires are part of Halloween, bats got indirectly pulled into Halloween.
cats dogs and other animals - Gamergirl989
Frankinstien, Witches, Vampires, Black Cats, Goblins, Bats, Mummies, Ghosts, The devil, The Moth Man, thunder bird, Aliens... PRetty much all scary things
vampires travel by walking or turning into a bat and flying most of the time. no that is not true! what happens is they can turn into cats not BATS. they do that or they just go runing. they are know to run at encredible speeds.
Figures associated with Halloween are ghosts, black cats, witches, jack-o-lanterns, etc.
The black cat
The connection between black bats, black cats, and witches is all based on old myths and fears, and now on advertising dollars.