What does it mean when someone says to be there eyes and ears?

When someone says "be my eyes and ears," it means they want you to observe and report back information for them. They are essentially asking you to:

* See what's happening in a situation they can't be present for.

* Hear what's being said, especially if it's confidential or sensitive.

* Report back your observations and findings, accurately and objectively.

Here are some scenarios where someone might say this:

* A parent asking a babysitter: "Be my eyes and ears while I'm at work. Let me know if anything unusual happens."

* A boss delegating a task: "Be my eyes and ears at the conference. See who's attending, what they're discussing, and let me know if there's anything important."

* A friend asking for help: "Be my eyes and ears at the party. See if you can find my lost phone, and let me know if anyone mentions me."

Essentially, it's a request for you to act as their proxy, providing them with information they need.