Hey Mr. Hitchcock your novel came to life!

If you’ve crossed a mockingbird somewhere along the way, be careful — it may have your number.

A new study published in the Proceedings of the National Academy of Sciences suggests that mockingbirds are particularly good at singling out specific people they don’t like.

In an experiment at a nesting site at the University of Florida, a human approached and threatened a mockingbird nest four days in a row. Each day, the birds retreated farther and farther.

But on the fifth, when a different human approached and threatened the nest in the same manner, the birds retreated only as far as they had on the first day with the original intruder.

The birds would also sound the alarm and attacked intruders that had previously threatened the nest while ignoring other people nearby. The researchers found that mockingbirds have a “remarkable ability” to distinguish one human from thousands of others, the article says.

What does it all mean? The article says it shows the birds may be better equipped to get along in human-dominated environments than many other birds by their “keen awareness of different levels of threat posed by individual of another species.”