Sentence 1: Lenny heard chirping as he walked by the holly tree in his yard. 
 Sentence 3: He carefully lifted it up and placed it in the nest with two others 
 Sentence 4:  He was worried the mother bird would reject this baby 
 Sentence 5:  But shortly after she came back with worms and fed all three of them 
 Option 1: He looked down and saw a mouse on the ground. 
 Option 2: He looked down and saw a baby bird on the ground.