No, they find it more probable that these particular signals are not aliens. It's not about whether or not you believe aliens exist, at all, it's about whether

No, they find it more probable that these particular signals are not aliens. It's not about whether or not you believe aliens exist, at all, it's about whether or not their the best explanation for any phenomenon. One day, we may get evidence for which there is no better explanation (say, a flying saucer landing at the White House with little grey aliens hopping out.) Right now, we do not have to use that hypothesis of last resort; it's still more parsimonious to think we just don't understand stars that well.