[On the regulation of the amount of prey in wood ants (Formica polyctena Foerster)].

In entire laboratory colonies of wood ants a withdrawal of prey results in a rise of the readiness for fight of the outdoor workers, and, after a new offering of prey, in an increased carrying in, whereby the deficit is more than counterbalanced. In spring this regulatory mechanism can be observed also in the field. In consequence of a want of prey first the readiness for fight rises. Then after an augmentation of the supply the quantity of prey carried into the nest reaches a maximum too. When the prey deficit is counterbalanced, usually at the end of May, both fall to a minimum. The greater the maximum of carrying in of prey is, the shorter is the interval between maximum and minimum. Thus the annual amount of prey is rather constant, even if the supply is varying.