There are actually quite a few ethnic groups within Nigeria. There are more than 500 languages and hundreds of ethnic groups within Nigeria. However the largest of these groups is the Hausa. The Hausa equal around 67 million in population. They make up 25 percent of all of Nigeria's population and are scattered all across the country.
All of the Hausa groups across the country are pretty similar to one another in customs and practices. They are known to raise cattle, grow crops, and do a lot of trading.