In the scientific method first of all is you need to identify the problem, the problem to your question is why does the dog circle its bed before lying down. Second is the observation to gather some data, you need to observe the dog if what could be the possibility the the dog may do that action. The third is the pre hypothesis, you need to came up with an idea why does the dog do such and action for example the needs to find a correct spot to make itself comfortable and lastly the hypothesis, this should answer to your question or your problem. So my hypothesis is that dogs are one of the animals that are those difficult to find a place to sleep and some of that kind of animals are cat, before they lay on their bed, they have to circle to find a spot that could fit its body to be more comfortable when the dog sleep
The correct asnwer to your question - why would a group of antelopes leave the herd for search of a better grassland is an example of emigration - B.
These antelopes would emigrate to a certain grassland and be immigrants in that grassland. This has to be distinguished.
I believe that the food web is more stable
That would be false. A catacomb is an ancient underground cemetery.
exact meaning: an underground cemetery consisting of a subterranean gallery with recesses for tombs, as constructed by the ancient Romans.