Insects, Spiders, Centipedes, Millipedes
Insects are the most successful of all animals in terms of speciation. That is, there are more species of insects present in the world than all other animal species combined. If biodiversity and persistence over time are used as gauges of evolutionary success, then insects are life's champions hands down. They are also integral members of the ecosystem, serving an essential role as pollinators for many plants. But though they are important and plentiful, ironically insects are one of the least known components of the park's natural resources.
Insects are invertebrates with three major body sections (head, thorax, and abdomen), six legs, and two antennae. Out of this commonality though insect species differentiate into a myriad of life forms. In Vicksburg National Military Park alone can be found beetles, butterflies, moths, damselflies, dragonflies, backswimmers, water boatmen, springtails, mayflies, midges, mosquitos, caddisflies, ants (including invasive red imported fire ants), and many others. Some of these insects are biters, others are suckers, while still others have evolved sponging mouthparts for lapping up liquids. Insects were the first taxon to take to the air when some of the member species developed wings. There are probably as many different insect forms as can exist in one's imagination.
Related to yet separate from the insects are the arachnids. This is a group of animals whose members include spiders and ticks. Arachnids are composed of only two body sections (the head and thorax are combined), they do not have antennae, and they move about on eight legs.
Both insects and arachnids have an outer, or exoskeleton. In order to grow these animals must molt this covering periodically. Some insects pass through distinct growing stages throughout their lives. They begin as eggs, become larvae, enter a pupal stage, and emerge as adults. An insect that goes through all four of these stages is said to perform a complete metamorphosis. Other insects perform simple metamorphosis. In this case there is no pupal stage, and the young are called nymphs (or naiads, depending on the species), basically smaller versions of the adults.
Perhaps because they are small, insects and arachnids are often overlooked. (At least until they find their way to your skin!) But they are deserving of much more study and attention than they are usually afforded.