Because they started breeding more started coming and there was no big threats
Crayfish are invertebrates which means they don't have a backbone. They are also arthropods, which means that they have a protective exoskeleton on the outside of their body. Other arthropods include insects, spiders, and centipedes. Crayfish continually shed their exoskeleton and regrow a new one. During this transition is when they are most vulnerable to predators because they aren't protected by their outer shell.
Crayfish are found all over the world in many different freshwater environments, such as rivers, creeks, springs, and swamps. But this doesn't necessarily mean that you will be able to find them. They are somewhat cryptic because they dig out homes for themselves under rocks and blend in well with their environment. Crayfish will ardently defend this dwelling against intruders using their strong front claws
Answer:b
Explanation:I believe it’s b I looked it up on google
Answer: Acid rain is a product of the <u>chemical reaction of sulfur dioxide and nitrogen oxide that is released with water, oxygen, and other chemicals into the atmosphere.</u> <u>Sulfur dioxide and nitrogen oxide dissolve in water and can be carried several miles by the wind</u>. After traveling for a long distance,<u> the two compounds become part of rain, sleet, snow or fog.</u> <u>Power plants emit sulfur dioxide and nitrogen oxide when fossil fuels such as coal are burned to produce electricity.</u> Aswell as <u>the exhaust from cars, trucks, and buses releases sulfur dioxide and nitrogen oxide into the air.</u>