They have heat within them for which leaf, bark, fruit, and flower are seen to fall off. They sicken and dry up. This indicates that they have perception of touch.
उष्मतो म्लायते पण त्वक् फलं पुष्पमेव च। म्लायते शीर्यते चापि स्पर्शस्तेनात्र विद्यते॥