PlayerMouse Button1Down/Up bugged?

local player = game.Players.LocalPlayer
local Mouse = player:GetMouse()

print("Running") -- Prints Running in output
Mouse.KeyDown:connect(function(key) print("KEY") end) -- Prints KEY after pressing random key
Mouse.Button1Down:connect(function() print("TEST") end) -- Prints nothing after clicking  (bugged?)
Mouse.Move:connect(function() print("MOVE") end) -- Prints MOVE after moving mouse 

Problem described above. Running this in a LocalScript located in the character model. No errors in output. Can someone confirm or am I missing something here?