Small insects (the most common) have a order 10,000 neurons. One estimate is 10^18 insects, implying 10^22 neurons. In humans it is 10^21 neurons total. However, smaller organisms tend to have smaller cells, so if you go by mass, humans might actually be dominant. Of course there are other groups of wild and domestic animals, but it gives you some idea.
Small insects (the most common) have a order 10,000 neurons. One estimate is 10^18 insects, implying 10^22 neurons. In humans it is 10^21 neurons total. However, smaller organisms tend to have smaller cells, so if you go by mass, humans might actually be dominant. Of course there are other groups of wild and domestic animals, but it gives you some idea.