Green’s Dictionary of Slang

(US) a person who loiters in hotel lobbies, usu. harassing guests.

1939		‘Hotel Sl.’ in AS XIV:3 Oct. 240/1: lobby-lice Loafers. [Ibid.] lobby lizards Loafers.
1954		Collans & Sterling House Detective 22: ‘Lobby lice’... were loungers, loafers and larrikins who hung around annoying, and sometimes swindling, desirable patrons [HDAS].
1962		S. Longstreet Flesh Peddlers (1964) 269: Two official lobby tarts (Bitsy said, ‘C.I.O. or A.F. of L.’) fixing their mouths, crossing their legs all the way up.
1971		R.D. Pharr S.R.O. (1998) 27: ‘Where were all the lobby lice the day I registered’.