Based on the results of this study, the Messor harvester ant is an appropriate factor for collecting some weed seeds around its nest. This study was carried out in saffron field in a completely randomized design with 5 treatment and 4 replications in Khalilabad city, Iran from the middle of August 2017. Treatment included: 1. Farm with presence of ants and without mechanical removal of weed seeds (control). 2. Farm with the presence of ants and mechanical removal of weed seeds 3. Farm with removal of ant (using Carbaryl insecticide 85%) and without mechanical removal of seeds 4. Manual weeding of weeds 5. Using of slim leaf herbicide (Gallant). Average seed hunting in treatment 2 in 1000 seeds, respectively,Wild barley (Avena sativa) 593.5,Wall barley (Hordeum murinum) 253.75,Camelthorn (Alhagi camelorum) 39.25,Whitetop (Caradaria draba) 35.5, Common lambsquarters (Chenopodium album) 27, Wild garlic (Allium ampelprasum) 19.5, Russian knapweed (Acroptilon repens) 11.75, (Lithospermum arvense) 8.5,Racemosum (Muscaria neglecta) 6.5, and Cleavers (Galium aparine) 4.75 . There was an ant outside the nest. Grown weed density of each treatment was counted using 1*1 square meter box. The highest weed density was related to H.murinum, A.sativa, C.draba (with average : 19.75, 17.75, 14.75 plants per square meter) in the third treatment, the ant removal treatment and the lowest weed density related to the fourth treatment , namely weeding of weeds, and the second treatment is the mechanical removal of the seeds collected by the ant. The amount of weed density is negatively correlated with the average of the hunted seeds, namely the higher the number of hunted seeds, the weed density is less. Therefore, according to the results of this study, the presence of ants and collecting hunted seeds mechanically by human reduces weed density in saffron farms.