Report Abuse. You should get them at 8 weeks old. That's an age where it won't be dramatic for them to be without their mother (or at least a caregiver that can take care of them 24/7) and old enough where you can start training. A lot of rescue center won't even give dogs younger than that.Silvia Â· 5 years ago. Thumbs up.eport Abuse. You should get them at 8 weeks old. That's an age where it won't be dramatic for them to be without their mother (or at least a caregiver that can take care of them 24/7) and old enough where you can start training. A lot of rescue center won't even give dogs younger than that. Silvia Â· 5 years ago.
Updated August 04, 2014. You can use a black light to detect body fluids. It's actually a good way to look for pet urine or make sure a bathroom or hotel room is really clean. Cat urine, in particular, glows very brightly under ultraviolet light. Urine glows under a black light primarily because it contains the element phosphorus.
Ultraviolet light frequencies are above violet on the spectrum and are invisible to the human eye. What you see glowing under a black light, whether on a fluorescent poster or an invisible hand stamp or a newly washed white T-shirt, are phosphors.e'll also see why black lights make some objects glow but not others, and we'll look at some interesting black light applications. If you turn on a black light bulb in a dark room, what you can see from the bulb is a purplish glow. What you cannot see is the ultraviolet light that the bulb is also producing.