Slave-Making Ants? - Formica

Only Formica species...

Are "slave-making", and mainly the sanguinea-group, to which the red species here obviously belongs. The "captive" (in fact, auxiliaries who have emerged here as imagoes, after having been robbed at the pupal stage) workers are from an all-black species of the fusca - group.
The slave-maker regularly attacks colonies of the "slave" species in order ot replenish its stock of (forced) auxiliaries.
Rare social parasites species do exist among Carpenter Ants, but they don't own a worker caste.

… Richard Vernier, 15 April, 2008 - 5:33am

Re: Only Formica species...

Thank you for the information, Richard. Will the Fusca-type auxiliaries help the Sanguinea-type ants raid colonies of their own species (i.e., raid their "birth colony")?

… Natalie McNear, 16 April, 2008 - 1:29pm

No, these ones don't help at raids

Most auxiliary species (at any rate, all black species) are specialized in brood care and inner nest maintenance in the nest of the "slave"- maker species, who takes over most external activities (foraging for honeydew and preys, and, of course, raiding fusca-group colonies when the stock of auxiliaries is depleting).
Indeed, presence of black auxiliaries often remains unnoticed unless a nest is disturbed, because they don't even go out (unlike specimens on your picture).

… Richard Vernier, 16 April, 2008 - 5:21pm

Thanks for the reply. I actua

Thanks for the reply. I actually did disturb the nest, which is when I saw the black ants. I lifted up the log they were living in while I was out looking for snakes, and I put it back down after I took the photo.

… Natalie McNear, 17 April, 2008 - 3:03am