The Messenger of Allah said: "If you cannot find anywhere (for prayer) except sheep's resting-places and camels' resting-places, then perform prayer in the sheep's resting-places and do not perform prayer in the camels' resting-places." (Using translation from Ibn Mājah 768)
"إِذا حَضَرَت الصلاةُ فلمْ تجدِوا إلَّا مرابضَ الغنَم وأعطانَ الإِبلِ؛ فصلُّوا في مرابضِ الغنم، ولا تُصلُّوا فِي أعطانِ الإِبلِ".