I kept several black widows many years ago. Do not keep them in the same jar. You will end up with one FAT spider! Do not leave eggs in with momma. When they hatch, they kill momma and each other until you have one fat spider. If you hatch eggs in jars with holes poked in the top, they are small enough when they are born to come out the holes. They are much faster than you think. When you open the jar to drop in food, they can run up your arm before you know it. They need very soft skin to be able to bite through, so they can't bite you in most spots. 90% of black widow bites are on the parts that hang through the hole in your outhouse! If you have an outhouse, occasionally, roll up a newspaper, light it and "flame" the underside of the seat. Only do this on a well vented outhouse. Methane gas is flammable. Black Widow lesson done!