Your baby can indeed feel and react to you touching your belly. The sense of touch begins to develop in babies during the first trimester; however, since the fetus is so small at this point, he or she may not be in contact with the side of your womb enough to register the pressure of your hand. As the baby grows and takes up more space, therefore having greater contact with the sides of the womb, he or she will be able to feel your touch much more consistently.
If you tap your belly when your baby is active in the womb, you'll often get a response from the baby to the touch. You can try responding in kind to the baby - when he or she kicks, tap in the same place - or initiating your own pattern of tapping in different places on your belly.