How might a cave an ant and a lake each meet the needs of an oranism

The organism could live in the cave, eat the ant, and drink from the lake.

The organism (s) will die. Any one of these needs are food, shelter, space, a safe place to raise kids, and/or water. Or the organism might have to move to a different area. That area might contain hostile creatures that would kill the organism, or it might eat something unfamiliar that was poisonous and it would die. There are stories of Jaguars who had been forced out of their home by deforestation. These jaguars are so desperate to survive that they turn to it.