Europe had a flea infestation problem for a while.
They <span style="font-style: italic">thought </span>they had a stray cat problem too.
But the biggest problem they had was the black death.
Of course they didn't know that the disease came from those fleas, which were carried by rodents.
Ironically, they also didn't know that the cats were the only thing keeping the rodents, and therefore the plague, in check and that the more they drove off the cats the faster they died from the plague.