My dd started to have an interest around 3.5 months old and was putting them in her mouth at 4 months old. Don't worry. Its normal to not be playing with them yet. Babies do things on their own time frame.
DS started grabbing them at about 3.5 months. At 4 months or so they started going into his mouth. Now he "plays" with them (usually just holding onto them and banging or swinging them) or sucks on them. If it's something hanging ( like the little cloth animals I hang from his car seat handle in the car) he'll swat at them. These must be the most fun activities ever, since he just laughs and laughs.