The digestive system - this part of an ant is used for digesting an ants food. When food is eaten,it passes on to the food pouch.This is where the juices are sqeezed out of the food.
The ant swallows the juice and spits out the solid part.The liquid goes to the crop,or social stomach.
An ant will regurgitate (spit out) from its crop to feed other ants.Some food goes to the midgut,where its digested.The undigested food passes out of the rectum.
http://www.ehow.com/how-does_5164970_do-ants-digest-food.html
Adult ants cannot digest solid foods.
Therefore,
everything they eat has to be turned into a liquid before it enters the digestive tract. When the ant eats a piece of food, digestive juices interact with the solid outside of the ant's mouth and dissolve the solid food into digestible liquid. The ant then laps up the food with its tongue.
Filtering
The food goes through the ant's mouth into a chamber below that houses a filter. The filter makes sure
no solids are allowed to progress. The solids in the chamber are compressed into one pellet, which the ant then spits out.