From Metroid Wiki
They have the same attacks as all other types of Shriekbat, namely colliding with their prey and exploding on them. Bryyonian Shriekbats also attack in swarms.
- "One of the many types of Shriekbats found across the solar system, the Bryyonian Shriekbat behaves similar to all of its cousins. Shriekbats will nest in small groups and make their home in a sheltered environment. Dwelling on the top of caverns and ruins, the Shriekbat will hunt nearby insects and small creatures for food. Once a nesting area has been found, it will be fiercely protected from any intruder. The territorial Shriekbat will dive-bomb any creature that wanders too close, no matter what the size." — Logbook "Bryyonian Shriekbat" (Metroid Prime 3: Corruption)