Place it at the reveal of the mouse, then follow it with Scream Meme for the reaction and Emotional Damage for the aftermath, keeping the mouse as the cause and the later clips as the response.
About this sound
This 5.7-second clip presents a mouse as a sudden scare, using a small, frightened creature for a much larger shock than its size suggests. It feels tense and unsettling at first, then oddly funny once the surprise lands, because the threat is tiny and the reaction it prompts is outsized.