How do insects use path integration for their navigation?

We combine experimental findings on ants and bees, and build on earlier mod els, to give an account of how these insects navigate using path integratio n, and how path integration interacts with other modes of navigation. At th e core of path integration is an accumulator. This is set to an initial sta te at the nest and is updated as the insect moves so that it always reports the insect's current position relative to the nest. Navigation that uses p ath integration requires, in addition, a way of storing states of the accum ulator at significant places for subsequent recall as goals, and a means of computing the direction to such goals. We discuss three models of how path integration might be used for this process, which we call vector navigatio n. Vector navigation is the principal means of navigating over unfamiliar t errain, or when landmarks are unavailable. Under other conditions, insects often navigate by landmarks, and ignore the output of the vector navigation system. Landmark navigation does not interfere with the updating of the ac cumulator. There is an interesting symmetry in the use of landmarks and pat h integration. In the short term, vector navigation can be independent of l andmarks, and landmark navigation needs no assistance from path integration . In the longer term, visual landmarks help keep path vector navigation cal ibrated, and the learning of visual landmarks is guided by path integration .