Let it be observed what a contrast the instinctive habits of F.

sanguinea present with those of the continental F.

rufescens.

The latter does not build its own nest, does not determine its own migrations, does not collect food for itself or its young, and cannot even feed itself: it is absolutely dependent on its numerous slaves.

Formica sanguinea, on the other hand, possesses much fewer slaves, and in the early part of the summer extremely few.