Give two ways that the activities of the caterpillar in the picture would change its ecosystem.

In certain group of trees, caterpillar create leaf ties that attract a group on insects that feed on those tied leaves thereby changing the ecosystem. There is a latest article in this topic in journal called Ecology.

Explanation:

feral cats are estimated to eat tens of millions of native animals each night in australia

the answer is true when observing or determining population size, a direct observation is use, in which each organism is counted in a population or in an area. one benefit of this measure is that you get the exact population count but it will take a long time to  determine  the  size  of a  population.