Two things really stick out to me in this chapter.
First, Pharaoh’s refusal to see that it is God, or to listen to God, is called sin. That means sin is not just doing something wrong, it is refusing to listen to God, and to do what He wants me to do. That means I have to be aware, and actively listening to where God is leading me. If I ignore Him, and choose to just do what I want (no matter how often I go to church or read my Bible), then I am sinning.
Second, God does not want to have the people of Egypt suffer; God cares for the animals of Egypt. Often God is accused of animal cruelty – because of the sacrificial system. The Lord cares for every living being on the planet, and chapters like this show us that God is looking out for the animals. Our God is love.