Cataglyphis fortis desert ants can learn visual or olfactory cues to pinpoint their nest, but only if these cues are unique to specify the nest entrance. Scientists from the Max Planck Institute for Chemical Ecology in Jena, Germany, discovered that the insects ignore visual landmarks or odors as nest-defining cues, if these occur not only near the nest but also along the route. Hence, ants are able to evaluate the informative value of such cues and are not fooled by ubiquitous unreliable cues.