It is narrated from Sayyiduna Abdullah bin Mughaffal (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "Pray in the pens of sheep, and do not pray in the pens of camels, for they were created from devils."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الصلاة / 4357