Bonnie bought a bag of birdseed. She left it in her apartment (#5) before she went to work, intending to fill the feeder that afternoon. But when she got back, the bag of birdseed was gone!

There were four other people living in the same apartment building as her, all of whom were avid birdwatchers like Bonnie. One of them must have done it. Look at the clues below. If you know everybody's name, apartment number (#1 through #4), and favourite bird, you will know who is guilty.

1. The guilty person's apartment number is not numbered one higher or one lower than Hal's.

2. Joe's favourite bird is the crow; his apartment number is one lower than that of Ike (who doesn't like robins).

3. The guilty person's apartment is not #3 (the number of the finch-lover's).

4. Gil is neither at apartment #1 nor the wren-lover.

Whodunit?

The Finch is Apt. #3. Thus Joe is not #3 or #4 (else Ike is #5). If Joe is #2, then Ike is #3, the wren is in #4 (2,3 filled, and not in 1); but then Gil is not in any apartment. Thus Joe is in #1; Ike is in #2, and likes the wren; robins in #4. If Hal is in #4, then the guilty party might be in 1,2, or 4, which contradicts the assumption that the guilty party can be found if all the names, numbers, and birds are known. Thus Hal is #3; so 2,3, and 4 are innocent. Therefore, the thief is Joe the crow-lover in Apartment #1.