The vermin of the earth such as snakes, scorpions, dung beetles, cockroaches, rats etc., are haram. This is the view of Abu Hanifah, Ahmad and Dawud (may Allah have mercy on them).

It was not narrated that the Prophet (peace and blessings of Allah be upon him) forbade drinking milk at the same time as eating fish.

Ostrich meat is halal because Allah has blessed His slaves by subjugating to them that which is in the heavens and on earth. For more about haram animal meat in Islam, see the detailed answer.