Although plants do not have feelings in the same way that we do, they can certainly response to different stimuli. They are able to grow towards a light source, even if turned upside down. Some plants have very sensitive leaves, which will fold up if touched. Others have leaves that open and close according to the time of day.
Venus Flytrap has sensitive leaf tips. When an insect lands on the tiny hairs on the leaf, the pairs of leaves snap shut, trapping the insect inside. Plants are even able to perspire. Although you can't see this happening, if you were to place a plant inside a plastic bag and fasten it, after a while you would see drops of water form on the inside of the bag. The moisture you can see comes from the leaves of the plant.
The Plant World
Some plants have sensitive hairs on their leaves. If an unsuspecting insect lands on these sticky hairs, it will quickly find its legs hopelessly entangled.