Why, because they won't get off your LAWN?
The Big Bang Theory Season 8, Episode 4
You found it. It's the sound of a cat
being run over by a LAWN mower.
The Big Bang Theory Season 2, Episode 15
...we had an inflatable Santa Claus
with plastic reindeer on the front LAWN.
The Big Bang Theory Season 3, Episode 11
so you could shoot hoops
and mow the LAWN?
The Big Bang Theory Season 12, Episode 3
If I mow the LAWN, can I have my allowance?
The Big Bang Theory Season 8, Episode 1