However," Maddison added, "there is a rate of false positives — my 'seeing' beetles where there are none, which I realize when I investigate further. The false positives are usually fairly low toward the end of a field trip, as I retrain my brain, but in some circumstances — i.e., a lack of beetles in the environment — that rate of false positives is higher, as my eyes don't naturally get drawn to the real beetles, instead latching on to whatever beetle-like blob is out in the landscape.