Mating fireflies. Urbana, Illinois, USA.
A small male Photinus pyralis firefly mates with a female. Small males aren't as luminous or easy to see as large males, but they are more agile. Field studies have shown that small males are more successful at mating than large males when many males are present. Urbana, Illinois, USA
A mating pair of big-headed flies. These small flies are parasitoids of Auchenorrhynchan sap-feeding insects. Austin, Texas, USA.
