Ants...

Walking around the Anza Borrego desert, I found lots of ant nests – all for some large (roughly 1 cm) shiny black ants that were very busy gather seeds.  You can follow their trails for a hundred feet or more, right to the plant that is their current source of seeds.  At the next, you can see the workers carrying some food item into the nest, and the empty-handed workers scurrying back out for their next load...