Thermal Monoculars detect heat signatures.  In the case of hunting, many farm fields have been invaded by wild hogs and boars at night . By using thermal monoculars, hunters can effectively control the invasion of these wild animals on their farm fields. Thermal imaging monoculars are  effective in total darkness or daylight and can see through obstructions such as smoke and fog. Heat detection is very different than starlight technology, where it allows you to scan large areas and find animals or people very easily. The thermal monoculars are also used in firefighting. Usually monocular can sense the heat radiations at the range of -50° C to 2000° C. Thermal monoculars extensively used in hunting, security, surveillance, energy analysis, LE and military, industrial applications and in search and rescue operations. As with any thermal device,  with a thermal monocular, one of the main factors that determines performance is the resolution or number of pixels in the thermal sensor - the more pixels the better the resolution will be. Thermal infrared imagers are detector and germanium lens combinations that give a visual representation of infrared energy emitted by all objects above 0 k. In other words thermal imagers let you “see” heat. Depending on the sophistication of your system thermography is capable of providing very detailed images of situations invisible to the naked eye. Thermal images cannot see through walls, although you can gather much information about the inside of the wall as well as what is happening on the other side of the wall.