Not all insects are bugs. True bugs form the order Hemiptera and include such critters as cicadas, aphids, planthoppers, leafhoppers, and shield bugs. Most bugs feed on plants, using their sucking mouth parts to get at the sap.

Here you can see a nymph of a Lygaeid bug, a Bagrada Bug, Milkweed Bugs, a Black Watermelon Bug, and a Shield Bug nymph.