Its average life span is 4 to 6 years, but some individuals may live to be 15 years old.
(Its average life span; is; 4 to 6 years) (some individuals; may live; to be 15 years old) (some individuals; to be; 15 years old)
Its average life span some individuals some individuals
is may live to be
4 to 6 years
to be 15 years old
15 years old