The idiom to have your ear to the ground means to be very attentive and tuned in to what is happening around you and to be aware of the latest developments and updates. Similar meaning expressions include to be 'clued in' or to 'have your finger on the pulse'.

1. I haven't heard any more news about Robert yet, but I'm keeping my ear to the ground so I'll let you know if I do.
2. You should ask Hazel to explain the situation to you. She always has her ear to the ground when it comes to politics.

1. My business relies on technology, which is why it's important I keep my ear to the ground so that I'm up to date with all the latest developments.
2. There has been talk of large scale layoffs at work. I need to keep my ear to the ground to figure out what's going on.