Experts and BHG readers answer.
Yes, you can put what hardware stores call "hardware cloth" at the bottom of a raised bed to keep burrowing animals at bay. It's a wire screening product that has quarter- to half-inch squares. It's kind of like chicken wire (which would work too to keep larger animals out). Spread it at the bottom of the raised bed and cover with enough soil so that you can plant the bulbs at the recommended depth. Check those requirements on the packaging with your bulbs.
Bulbs like to be cold in the winter. In fact, many (like tulips) won't bloom with out a cold period, so yours should be fine in a Zone 7 raised bed.