There is a need in firearm training for reactive targets. When marksmanship has been attained and defensive skills are being acquired, targets that give instant feedback are invaluable to the student-shooter. Knowing you have missed causes stress and requires self-discipline to correct your shooting. That’s good experience to have in your training.
There are many reactive targets made of all sorts of materials. Some swing and drop, others explode in colors, and some just make noise. For economy and versatility, I prefer a cheap bag of party balloons. Different colors allow you to conduct simple shoot/don’t shoot scenarios. They make noise. You can fill them with smoke or liquid, and depending how much you blow them up, the size of the target can be controlled. Balloons can be affixed to almost anything, and they’re easy to clean up, with no debris left on the range.
For a dollar at the party store you can enjoy the cutting edge of “Audio/Visual Reactionary Firearm Target Devices.”