Ju malpli mi dormas, des malpli mi sentas la bezonon dormi = The less I sleep, the less I feel the want (need) to sleep.
Ju malpli mi dormas, des malpli mi sentas la bezonon dormi = The less I sleep, the less I feel the need (to sleep) of sleeping.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "sentas" in a variety of sentences. We hope that you will now be able to make sentences using this word.