The Blood-red Slave-making Ant (Formica sanguinea), or Robber Ant, is a species of ant in the Formicidae family.
This species is named for the fact that this species will break into other ants, nests, notable F. fusca, and steal their larva and pupa, these are then raised and used as slaves. This species is bright red with a grey abdomen. This species is similar to wood ants, but have a median anterior notch in the clypeus, and also rarely raise their gaster (abdomen) to eject formic acid. This species is found in south-east Enlgand, Scotland, and a few locations o the Welsh border. Usually found in heathland or open woodlands.