Abstract: Insecticidal fogging has proven to be an efficient method for sampling arboreal arthropods in tropical lowland rain forests. By exact positioning of the collecting funnels beneath the tree and by excluding arthropods from higher canopy levels, fogging can be a precise tool to collect for example ant communities in a tree-species specific way. Such clearly defined communities form a good model system for community analysis. Analysis, however, requires knowledge about how representative communities were sampled from the trees. In order to assess this, ant nests were located in the trees the day before fogging. For that purpose ants were attracted to bait (pieces of tuna and sugar-water) placed on all branches in the trees. Pursuing the ants from the baits made it easy to localize the ants' nests in the trees and to get information on the relative size of the colonies. Comparing these results with those obtained by fogging showed that fogging does not always describe abundance hierarchies correctly and that different species could be numerically dominant at the bait compared to the fogging samples. Particularly, abundances of stem-nesting species are underestimated indicating the necessity to correct ant abundances for a specific community-level analysis.