Firstly, the population density of mice without interference (no drugs, no introduction of natural enemies) is obtained, that is, the stable solution.

1. A variable is introduced to measure the effect of rodenticide delivery intensity as a disturbance. Observe the fluctuation of equilibrium state. The effect of rodenticide on rodents and natural enemies (changing with time) was obtained. Discuss it.

2. A variable is introduced to measure the population density of natural enemies, and a stable solution is obtained. Compared with 1. You can know the long-term effect, which is better or worse.

During this period, the population density of mice in the stable solution of 1 and 2 was the lowest by adjusting the parameters. That is, the rodent control effect is the best. If the capital * mouse density is the lowest in the stable solutions of 1 and 2, the effect input is optimal.