Ants use their front two legs differently from the back legs. They may use these limbs to dig or hold objects in place when manipulating them with their mandibles. The coxa of the front leg is often longer while all of the other segments are shorter. Ants have a comb on their front legs which they use for grooming—
I don’t think the front legs are used for manipulation in enough ways to have that be their primary purpose but there is a distinction that makes them more like “arms”