A guard dog would help in identifying threats as well...
My 100lb female German shepherd can wake me up pretty darn easy if somethings up.
If the key-on-a-lightstick method is feasable then do it. If not, then boot the door.
NCO of Marines, 3rd Award Expert Rifle, 236 KD Range
D Co, 4th CEB, Engineers UP!! OEF 21JUN-20SEP2011
REV. 19:11 And I saw heaven opened, and behold a white horse; and he that sat upon him was called Faithful and True, and in righteousness he doth judge and make war.