Thirst is used to make an animal realize that it needs to replenish its bodily water by the body, and water Water in the area's natural water bodies is drinkable as such. Given these facts, what is used to make an animal realize that it needs to replenish from a natural drinkable source among the following options:
- spring
 - excretion
 - blood
 - pain
 - thirst
 - tiredness
 - hunger
 - rain


 

     thirst    