How to keep birds out of front door wreath?

I just took down my fall wreath the other day. The final days it was up we had birds living in it. When we opened the door they flew inside the house. Luckily DH had a net and got them out. I took the wreath down and we just recently put up a wreath made up of shatter proof onrnaments so there is no greenery. When DH left for work this morning he thought he heard them on the wreath so he shut the door quickly so they wouldn't fly in again and left through the garage. The fall wreath had flowers and fall dried grasses so I guess an ideal home for some birds. But what's up with the ornament wreath?!?! How do I keep them off? If there is no solution, I'll just take the wreath down but I don't want to. We put up wreaths every year and have never had this problem. I can't keep having birds fly in the house!