Temnothorax pilagens (from Latin: pilare, "to pluck", "plunder", "pillage") is a small Nearctic species of slave-making ant in the subfamily Myrmicinae.

Occurrence is patchy and depends on high density of suitable host populations; so far only known from three sites in the northern US: Niquette Bay State Park (Vermont), E.N.

This is especially true for the frequent and effective use of the stinger in fights: well-aimed stings from a caudal direction between head and thorax cause paralysis in hosts followed by quick death.

Effective sting use is likely facilitated by morphological adaptations, such as strongly developed flexor-muscles in the petiole and postpetiole allowing for easy gaster flexion.

Due to their most effective stinging behaviour, Temnothorax pilagens can cause high rates of host casualties (ranging from 5% to 100%).