The effect of surface soil temperature on attraction of foraging red imported fire ants, Solenopsis invicta Buren, to a food lure in centrifuge vials with access 2.54, 5.08, and 7.62 cm below the surface compared with vials horizontally at the soil surface or in the soil with the opening at the soil surface was monitored in the Coachella Valley of California. Analysis of variance showed no significant differences in the mean numbers of ants collected in the three strata, indicating a 2.54-cm opening as preferable, or when compared with vials horizontally placed at the soil surface or with the opening at the soil surface. However, during summer days, vials baited with subsurface food lure attracted 10–30 more foraging worker ants compared with vials horizontally placed at the soil surface or with the opening at the soil surface. Use of this method could provide more consistent data on monitoring ant foraging and result in fewer false negatives.