Adults signal the presence of the toxin via their orange coloration. A bird that tries to dine on the queen, monarch or soldier (or a third, distant cousin, the viceroy) isn't likely to repeat the mistake. The easiest way to tell the species apart is this: soldiers and monarch (and viceroys, which closely resemble monarchs) have dark, heavy veins on the upper side of their wings; the veins on queens are fine.

Queens and its cousins are member of Nymphalidae, or the brush-foot family.

Queens are found in Texas and Florida, south through the Caribbean and Central America to Argentina. They have been known to stray as far as Massachusetts and the Northern Plains.

Queens are large as butterflies go, with a wingspan that approaches 4 inches. Adults dine on the nectar of various flowers, including Spanish needles and milkweeds, as shown in the photos. They like fields, roadsides and dunes.