Ants estimate area using Buffon's needle

We show for the first time, to our knowledge, that ants can measure the siz e of potential nest sites. Nest size assessment is by individual scouts. Su ch scouts always make more than one visit to a potential nest before initia ting an emigration of their nest mates and they deploy individual-specific trails within the potential new nest on their first visit. We test three al ternative hypotheses for the way in which scouts might measure nests. Exper iments indicated that individual scouts use the intersection frequency betw een their own paths to assess nest areas. These results are consistent with ants using a 'Buffon's needle algorithm' to assess nest areas.