As you probably know, brains of humans and other vertebrates consist of two halves, called hemispheres. By and large, both hemispheres carry out the same functions, but they are not identical. The best known asymmetry between the two hemispheres is the lateralization of language: The left hemisphere is dominant when it comes to language. Another obvious example is handedness: The right hand is primarily controlled by the left hemisphere, and vice versa, so handedness reflects a hemispheric specialization in the control of hand movements. Again, the left hemisphere is usually dominant.
The list goes on and on. Everywhere you look there are differences between left and right, which can often be traced back to asymmetries between the left and right hemispheres. Some differences, such as handedness, are obvious, some are subtle. And some are rather cute.
A while back I read a paper by Giorgio Vallortigara, one of the experts on lateralization, in which he made "a stroll through animals' left and right perceptual worlds." One figure in particular stuck in my mind:

So what are we looking at here? Vallortigara and colleagues investigated the predatory behavior of toads using the "worm test". They suspended worms, which toads enjoy very much, from a thread, and slowly brought the worms into the toads' field of view. Sometimes the worms entered the toads' visual field from the left, and sometimes from the right.
What the graph shows is that the direction from which the worm enters the toad's visual field makes a …