I always pack a Mouse Squeaker along with me when I'm Hunting or just checking trail camera's,You never know when it will come in handy...or as several mentioned I have lip squeaked in Coyotes also.
All Squeakers are not created equal..I've had a few cheap ones that were round and I've losted them,had them drop/roll off my ladder stand seat and other flat surfaces.The best Squeaker I have now and probably need to buy a spare one is the Primo's green colored Mouse Squeaker,it is 1/2 rounded and flat on the bottom,fits great inside a shirt pocket and won't roll off things when You lay it down!
This year I called in a Bobcat with my FoxPro Shockwave Caller,it walked out to the Caller about 35-40 yards into the Field I had it set up in while trying to call Coyotes,I turned the Caller off when the Bobcat made its way out to it then started to use my Primo's Mouse Squeaker and it walked back towards me and walked back into the woods to the right of my stand!Pretty Cool experience and the Squeaker brought the Bobcat right past me and I video-ed it on my cell phone...the Bobcat was out of Season so I wasn't able to shoot it! 
