Are all Black Widow Spiders Poisonous?
Not all Black Widows are deadly. The adult female Black Widow’s poison can be deadly, but male and juvenile Black Windows are essentially harmless.
FACT: All Black Widow Spiders are all carnivorous and can bite, and all have poison glands, but only the female Black Widow spider’s venom can kill people, with the young or sickly being most at risk.
How Poisonous are Black Widows?
The male and juvenile Black Widow spiders are harmless to humans despite being carnivorous. Males have smaller poison glands and fangs than females and juvenile female spiders haven’t yet developed the means with which to deliver a deadly bite. On the other hand, the female Black Widow spider’s venom is fifteen times as lethal as the prairie rattlesnake. 
What Happens When You are Bitten by a Black Widow?
Bites produce nausea and muscle spasms, which can prove fatal if they paralyze diaphragm or cause seizures. However, because spiders do not inject much venom in a single bite, their bites are unlikely to be lethal. To see a video about these spiders see this Black Widow Spiders-Video.
How poisonous is a black widow?
Fun Fact: Widow Spiders are web spinners and belong to the genus Latrodectus and family Theridiidae, There are six species, which live in most warm parts of the globe.
What Should I do if I am Bitten?
If a Black Widow Spider bites you, you should seek medical attention because the toxins may lead to seizures or death.
Try to capture the spider for identification if possible. When a Black Widow bites, they puncture their prey, almost always an insect, and inject a digestive enzyme to liquefy their meal’s body so they can suck it up. This can produce a painful bite for a person at the very least.
The Black Widow Spider. Black Widow Facts. How to get rid of black widows. TheCoolFactShow Ep. 10
Do the Females Really Eat the Males?
The female Black Window Spider does not eat her mate unless he remains in her web after mating. If he does not leave, he may be eaten at a later time. The Red Widow eats her mate when he places parts of his body in her mandibles. If she does not eat him the first time he tries this, he repeats the behavior until she does eat him.Male Black Widows can only mate once. Even if they remain uneaten, they are sterile after discharging sperm into their pedipalps.
Deadly Mates: Black Widow Spider