Mice haver a reason to be jumpy and paranoid, especially when cats are around, trying to hunt them down and kill them. That’s why scientists are still puzzling over a parasite called Toxoplasma gondii.

After this parasite infects rodents, the rodents gradually become less fearful of cats, making them more prone to being caught and killed by a cat. Research indicates that this same parasite could affect human beings the same way.

So perhaps people who love cats don’t do it because they find cats adorable, but because their brains have been infected by a parasite that’s making them like cats even more. Who knew that cats could wield such a potent biological weapon against the human race?

To learn more about this parasite that makes mice less afraid of cats, click here.