On a cold spring day, harvester ants cluster around their nest entrance to warm up in the sun before heading out to forage.

Frank Raines State Park, California, USA

Messor andreiVeromessor andreimyrmicinaeformicidaeantsantinsectsthermal ecologysocial insectssuperorganismant nestants nesthymenopteraanthillant hillant moundant swarmharvester antsseed harvestersworker ants