Fields have eyes, and woods have ears

Fields have eyes, and woods have ears.

Prov. Even though you are outside in an apparently empty landscape, someone may be eavesdropping on you. Jill: You said you had a secret. Tell me. Jane: Not here. Jill: But there's nobody else in the park. Jane: Fields have eyes, and woods have ears.
See also: and, ear, Field, have, wood