Depends, Logitech G7 mice have their frequency coded by their usb dongle, you cant change them, but there is very little chance of interference (if you have 10+ mice you might have a problem

)
On the other hand, The older 27mhz radio keyboard/mouse desksets only had two channels, and have considerable problems with interference. I found the best success was to have one computer to have channel 1 for both keyboard, and mouse, and the second computer to have channel two.
If you have a Bluetooth keyboard/mouse, then it will negotiate with other bluetooth devices in the room and generally be pretty much trouble free. Even older logitech desksets ran on yet another frequency set, so different models sometimes dont conflict. Bluetooth will not interfere with the 27mhz models, or a G7 mouse.
So basically it all depends what models you have.
I have three computers, ended up selling one of my wireless keyboard/mouse desksets because there was constant interferance problems. Replaced my main PC's with the bluetooth version of the keyboard +mouse combo, and now all 3 computer are interference free.