What is a grey black hard shell bug in Florida?

A grey-black hard shell bug commonly found in Florida is likely a type of beetle, such as the Florida potato beetle or the darkling beetle. These insects often have a tough exoskeleton, which provides protection. They can be found in various habitats, including gardens and woodlands, and may feed on plants or decaying organic matter. If you need a specific identification, consider consulting a local entomologist or pest control expert.