A titmouse is a very small insectivorous bird that come from the family Paridae and are only found in the northen hemisphere and Africa.
The name titmouse is attested from the 14th century, composed of the Old English name for the bird, mase (Proto-Germanic *maison) and tit, denoting something small. The spelling was influenced by mouse in the 16th century.
"What the hell is that on my window ledge?"
"Don't worry dude, chill, its just a titmouse."
A timid man who is nearly always staring at womens' breasts, but just can't work up the nerve to speak to one.
"Bek, button a button. You have a titmouse at ten o'clock," Cherry said, tucking a scarf into the front of her dress to discourage the creepy little man.