When I first came to California I was driving west on I-80 and I was stopped at the Nevada border. But they just asked if I had any plants or animals in the car

When I first came to California I was driving west on I-80 and I was stopped at the Nevada border. But they just asked if I had any plants or animals in the car and when I said no they left me alone. Apparently they are very concerned about invasive species. Hawaii is similar.