In science we played a simulation game called Shark Tank. In the game we had three species. Sharks, minnows, and seaweed.  At the beginning of the simulation we had  1  shark , 4 minnows and 14 seaweed.  In real life sharks would eat the minnows and the minnows would eat the seaweed.  Since sharks are very fast they could run to get the minnows.  Minnows could not go very fast so they had to walk.  And the seaweed had to stay planted on the floor.  We all had to come up with strategies to help most of the species survive.  Different kids had different ideas. Then we all agreed on one idea. Since there were 4 minnows then two of the would sacrifice themselves and die and the other two would eat 2 seaweed. One seaweed to survive and one seaweed to reproduce. That would also help the shark. It would let  the shark survive.  This strategy also benefited the seaweed.  Every seaweed that survives gets to reproduce.