On this page of the game guide to Borderlands 2 you will find a detailed description of the side mission titled Animal Rescue: Food, Shelter. You can begin this quest in the Lynchwood location after the completion of the side mission named Animal Rescue: Medicine.
2) Skag area
4) Old mine
Your task will be collecting five Skag Tongues. They can be collected from the corpses of killed Skags which you can come across in the area marked as . After you collect enough of them, return to Dukino . Place the food in the designated place and end Food to begin Shelter.
After accepting the mission , follow Dukino towards the old mine . Ride the elevator down  to the cave. Here you will have to face a big group of Bandits. Eliminate them all and approach Dukino to end the mission.