School of immature Bullhead Catfish (Ameiurus nebulosus). The Brown Bullhead Catfish can be found in impoundments, ponds, lakes, and streams with soft bottoms from Canada to the southern United States. It is native to North America but has been introduced to many countries throughout Europe, as well as Chile, Puerto Rico, and New Zealand. Approximately seven days after hatching, young Bullheads leave their nest in a large school consisting of hundreds of individuals. One or both parents usually accompany the school until it breaks up a few weeks later.