Welshies
Crowing
Or red ones. Many livestock compa ies use red heat bulbs.Stores like Home Depot, Lowes, Walmart, Target, etc do not sell bulbs labeled for brooder/poultry use, but that doesn't mean you can't use them. Of course check the box for warnings, but also check the look of the glass. Teflon coated bulbs are opaque, so do not use anything opaque. Also do not use anything that says "shatter proof".
All clear non-coated bulbs should okay to use.