The influence of Guarea guidonia (L.) Sleumer diaspore abundance on ants’ preference was studied in a secondary tropical forest area in Brazil. We offered seeds in stations with different abundances (one, two, five or 10 diaspores) for interactions with ants. The number of interactions and of ants were influenced by diaspore abundance during the observation period. Stations with 10 diaspores maintained a high number of interactions throughout the experiment. Incidence of seed cleaning differed among the four groups. Moreover, the number of interactions was positively related to the average percent of seeds cleaned. Diaspore abundance proved to be important for promoting more interactions with ants. Considering that the proportion of seeds cleaned increased with the number of interactions, further experiments should observe ant activity for a longer period. Furthermore, diaspore abundance should be considered in future studies of interactions with ants.