Sayyiduna Jabir (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Do not let your animals and your children out at sunset until the darkness of the evening has passed, for the devils are let loose at sunset until the darkness of Isha has passed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الحج / 10345