Simplify the following text for a Grade 7 native English-speaking person.
Original: Other birds such as orioles and jays have learned to eat only the thoracic muscles and abdominal contents because these contain less poison than the rest of the body .
Simplified: Other birds , such as orioles and jays , have learned to eat only the thoracic muscles and the body parts inside the abdomen . These parts have less poison than the rest of the body .