The animal exhibits a low population density and requires a very large home range.

Each animal required at least a two-second burst from the weapon to get knocked out.

Other animals required "genetic adaptation" but survived in some form or another.

The thing looked huge, but then large animals can require large amounts of medication.

All animals require a source of oxygen to live.

L: "Of course, a sound animal will require very special treatment en route."

Large animals such as elephants require many years before they reach a useful size.

These animals will require undisturbed land set aside for them.

The animals also require ultraviolet light, thus they should be allowed to bask in the sunlight daily, but for only a short period of time.

These animals require food and care in order to produce more valuable products.