Based on what i know of bats they have echo location to help them navigate were they are going and the echo location helps them to find food.a special feature that they have to help them survive is their hearing do to their lack of eye sight they compensate with unnatural hearing.
A river forms from water moving from a higher elevation to a lower elevation, all due to gravity. Flowing water finds its way down a slope initially as small creeks. As small creeks flow downhill they shape larger streams and rivers. Rivers eventually end up flowing into the oceans with much more speed than was originally there.
Hope it helps and I did it correctly and used that words I needed to.
