True. This is because they form the lowest parts of the food chain. These invertebrates at young stages are generally exposed to the harsh environments around them. Being organisms that have not developed their mechanisms for protection these invertebrates will be subject to bigger animals and will serve as an easy prey. These invertebrates can be easy prey to larger organisms like birds and frogs, that mostly feed on insects and soft organisms. The saying, "survival of the fittest," is always true when it comes to the ecosystem.