Which insects are known for being small, dark, hard-bodied, and laterally flattened with no wings?

Fleas are accurately described as small, dark, hard-bodied, and laterally flattened insects, with no wings. They possess these characteristics due to their adaptation for a parasitic lifestyle, which involves jumping onto and off of their hosts. Their flattened bodies allow them to move easily through the fur or feathers of the animals they inhabit. Unlike other insects, fleas do not have wings, which is consistent with their mode of life that relies on strong hind legs for locomotion rather than flight.

In contrast, beetles possess a hard outer shell and are known for their diverse shapes and sizes but may not always be laterally flattened. Termites, while small and sometimes hard-bodied, typically have a more elongated shape and are social insects, often found in colonies. True bugs, like aphids or cicadas, also have wings in their adult form and do not fit the description of being laterally flattened and wingless.