Where I live it tends to get pretty cold in the winter, so I wanted some of your suggestions on ways to keep my coop warm. Here are my questions... 1. Should I coverup the ventilation on the top/side of their coop to minimize cold air getting in? 2. Should I get a heater of some sort to put in their coop? 3. If you think I should get a heater, what are some good brands of heaters that will not burn down my wooden coop? 4. Are there any other things you recommend for me to do to keep my ladies warm? Any help is appreciated!!! Thanks!