Yes, however keep in mind you are viewing the infrared energy from heat, and it's the differences in temperature that provide your image. This means the closer your target is to it's surroundings, the less obvious it will appear.
yes you absolutely can , that's one of the reasons I bought this vs night vision. and this is actual thermal, so day or night. some of the reviews weren't so impressed with it, but I can tell you, it is great. I would definitely recommend this scope.