FWIW, I have a little handheld thermal by armasight, being sold by covert optics that does well spotting just about anything that has heat above ambient temperature.
It doesn't record, but I was able to try to hold the thermal and my cell phone towards the screen last weekend to show one of my buddies that it would pick up small animals too because he wasn't sure how well it would work for that.
Obviously, the lines you can see on my cellphone is the refresh rate. You can't see those with the naked eye.
