A nature reserve.
should brakes be kept in a good condition
In its natural habitat the frog populations are kept small by natural predation, specific parasites and a harsh living condition. Without these the frogs can spread very rapidly.
A wildlife sanctuary or natural reserve where animals are kept in their natural habitat for research purposes.
what natural occurrence kept the indus balley supplied with plenty of water
Messy area/area where pigs are kept
It kept out invader's.
As long as they are getting as much natural lightas they want, and the area they are kept in is cool/well ventilated/clean/plenty of space, then no - they will not get sick.
mintcondion
The area of Tandy Hills Natural Area is 647,497.027584 square meters.
The area of Johnson Run Natural Area is 874,120.9872384 square meters.
The area of Sielbeck Forest Natural Area is 1,558,039.7226240002 square meters.
The area of Tideman Johnson Natural Area is 31,120.325888256004 square meters.