Answer:
nobody
Step-by-step explanation:
Humans have made use of natural numbers as long as humans have been around. Counting numbers are wired into our consciousness, as they are for many living things.
Research has demonstrated some plants can count up to 5 (generally, carnivorous ones). Honeybees have long been known to be able to count to 4, and recent research shows they can count higher. Fish can count; birds can count; as can many other species.
For most, it takes concentration and/or training to count beyond 4. We are born with an understanding of 1, 2, 3, more.
Nobody "invented" natural numbers.
_____
<em>Additional comment</em>
Prey species survive by being able to count predators. Some predators take advantage of the limitations of number recognition by hunting in groups larger than can be readily counted.
