Some species of spiders do eat ants and some, like the Euryopis superba, prefer ants over other insects. Black widows and lynx spiders target ants for prey when given the opportunity. Some jumping spiders eat plant nectar and may consume ants or other insects that might harm the plant.
Spiders eat a variety of insects, with many eating any insect caught in their web. On the other hand, many species of ants commonly kill and eat spiders as well. The spitting spider found in the Phillipines eats jumping spiders, which prompts the jumping spiders to build homes near weaver ant nests. Weaver ants eat spitting spiders, and their presence keeps the spiders away.