I've heard it many times but only in media related to Japanese and chines vampires; I'm guessing that its a cultural thing
Although here is something I found from a quick search if your interested.
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Lisa Savignano
Former Library Assistant at Ocean County Library (2000–2015)Author has 5.9K answers and 3.7M answer views
1y
Vampires counting seeds and/or rice grains comes directly from folklore, mostly that in Europe. Some legends carry it even further and say vampires are also compelled to count holes in fishing nets. Strangely, this version only appeared along the coasts in Slavic countries…
In Europe, the seeds usually have to be millet and/or poppy seeds. In China, if a vampire came across a sack of rice, he or she would be compelled to count the rice grains. Very occasionally, it had to be mustard seeds. This seems to have disappeared from most modern vampire stories and mythology. Nobody is sure why.
But vampire myths and legends are usually very strange and/or contradictory. For every “Vampires can’t stand and/or are destroyed by sunlight”, there are stories of vampires working as laborers- all day. For every “Vampires are dead bodies only motivated by lust for blood”, there are stories of vampires returning to lie with their wives, who then get pregnant from them (These are children are where the legend of “Dhampirs” come from). Some vampires can actually eat food, but gain no nutrition from it.
Each folkloric vampire is its own animal, from the Alp to the Penanggalan of Malaysia. Each is slightly different, so if you are interested in a specific vampire of folklore, I suggest you look up that variety. And don’t forget the Jiang-Shih, or the Chinese Hopping Vampire.'
Thanks everyone at
Cryminals Syndicate for the translation