There is plenty of evidence that most animals have evolved optimal or near-optimal strategies when foraging. Birds and mammals cover huge areas in their foraging trips and do so by local searches combined with long-distance translocation. In other words, there seems to be a rule governing many animals that says: search at one location exhaustively, then move to a different spot. Compared to a completely random walk or flight, this strategy effectively covers a larger area. One can show mathematically that a certain relationship between these short, local displacements and the long-distance displacements constitutes an optimal search strategy for randomly distributed, scarce resources and many animals follow such a rule. Now, Andy Reynolds (Rothamsted Research, UK) and Mark Frye (UCLA) have discovered that fruit flies ( Drosophila melanogaster) use the same optimal strategy and published their important discovery in PLoS One. It means that flies don't buzz around aimlessly, but rather have a probabilistic search strategy which has evolved in evolution. Only those flies survived which could maximize their search efficiency. This finding has received quite some press coverage (1, 2, 3) and is important for my own research as well.
Testing for this optimality is done by looking at the distribution of long vs. short displacements. While Reynolds and Frye looked at freely flying flies, we analyze tethered flight in our project on spontaneous behavior. We also find such optimal strategies when we analyze our data. Most importantly, we even find them when the flies are flying in a uniformly white environment, with no feedback as to how far they have gone. This means that these search strategies are programmed into the brain of the fly and rely mostly on timing rather than spatial cues. Interestingly, these strategies are not random but nevertheless indeterminate.