Seneca Lake contains populations of largemouth bass, crappies, bluegills, bullheads, channel catfish, and walleye. Fish present are bass, walleye, northern pike, channel catfish, bluegill, crappie, and bullheads. Yellow bullheads, yellow perch, and redear sunfish can also be found. Because they have an unforked tail, many people mistakenly think small flathead catfish are bullheads. Channel catfish, bullheads, and madtoms are "bottom feeders" with widely varied diets that include scavenging. All three major bullheads can be confused with other catfishes by novice anglers. Brown bullheads have camouflage coloration to avoid predation. Brown bullheads are the most abundant species in many lakes and streams continentally. Brown bullheads are ectothermic, heterothermic, and bilaterally symmetrical. Brown and yellow bullheads are significantly smaller. Brown bullheads are typically nocturnal feeders, but have been reported to feed diurnally. Brown bullheads have additionally been recorded eating their own eggs occasionally. In many areas of the United States, brown bullheads are opportunistic bottom feeders. Black bullheads start to spawn in April and continue through June. Black bullheads also occur as an invasive species in large parts of Europe.