Monarch butterfly
The female lays her eggs one by one. They are laid on the underside of the leaves of caterpillar's food plant. The eggs are light yellow. Freshly laid eggs are creamy-white. After three to four days, they turn dark gray. The egg usually weighs about 0.54 milligrams. It is about 1.2 millimeters long. Its diameter is about 0.87 millimeters (average on 55 eggs).