Are there security devices in merchandise other than the ink tags?

in stores such as macys and jc penny and department stores as those. because a lot of times after I pay, the alarm stil goes off even if tags are removed. are there any security devices concealed or something??

You know, it might be what you're wearing, because I've sometimes gone in shops and the alarm's gone off when I've not even bought anything!! I think the alarms might be sensitive to certain metals or something. It's so annoying because everyone always gives me dirty looks..

Sometimes cell phones can set off those alarms.