What could this creature possibly be? Here’s a hint. The picture is greatly magnified. The creature is actually only a few millimeters long. Now can you guess what it is?
The organism in the microphoto is an insect commonly called a bedbug. Insects are invertebrates in Phylum Arthropoda. Insects may “just” be invertebrates, but they are surprisingly sophisticated animals. They have a brain, for example, and multiple sensory organs. Some insects even live in complex societies. Insects evolved relatively late in invertebrate evolution, so they are fairly complex as invertebrates go. Many other invertebrates are much simpler. The simplest invertebrates are sponges and cnidarians.