The Unggoy, having such a lowly place in Covenant society as cannon fodder and subservient thralls, lead an existence of servitude and feeding at these nipples is one of their very few real pleasures. Many Grunts do not enjoy feeding off of Food Nipples; however, they seem to just put up with it because it is their main source of nutrition. They appear as a long tube with a nipple at one end to consume from, and contain a blue, bubbling paste that the Grunts find unappetizing but nutritious. McKay describes the smell as "old socks wrapped in rotting cheese."
They are described as free standing food-dispensers, with long tubes and receptacles that end in a nipple the Grunts use to distribute the food into their gullet. Grunts seem to form a bond by sharing food nipples.
- The Thirsty Grunt in Halo: Combat Evolved says "Good thing the food nipple's waiting for me back at the star ship, 'cause man, have I worked up a big, Grunty, thirst!"
- On Bungie.net, one of the avatars sports a Grunt Ultra with a piece of cardboard saying "Will work for Food Nipple."
- The Grunt who mentions Flipyap also mentions that they "went to Nipple Academy" together.
- Also, in Halo 3, if IWHBYD is turned on, a Grunt may say: "He flees! Thank the nipple..."
- In Halo 2 on the level The Oracle, after the grunt says he has a bad feeling about something, another grunt says: "You ALWAYS have bad feeling! You had bad feeling about morning food nipple!"
- In a cancelled animated episode of Red vs Blue, a Grunt amongst a large group of Unggoy can be seen eating from a Food Nipple.