But if there are 10,000 to several million of them, then the odds of detecting a signal go up as we look at more stars. Of course if there's only a few, then w

But if there are 10,000 to several million of them, then the odds of detecting a signal go up as we look at more stars. Of course if there's only a few, then we might not see any evidence for them. But 10,000 would probably be detectable at some point in our search.