If you notice a device that shouldn’t be on your network, you can restrict it from accessing the internet by blocking it from the connected device list.
In the eero app, tap on the Devices tab to open the list of connected devices. You should see devices separated by category, with recently connected devices appearing below this.
You can tap on any device on this list, press the three dots in the upper right corner and select Block Device to disable network access on that device.
Blocked devices will now appear in a new list that populates at the bottom of the Devices tab. You can tap on any device on this list, select the three dots in the upper right corner and select to unblock. This will remove it from the block list and re-enable network access.
Note: Device blocking is not available in bridge mode.