Breeding tarantulas can be extremely difficult but can also be extremely rewarding. From a successful mating, anywhere from 50 to 2000 eggs can be produced, depending upon the size and species of the female. The Brazilian Salmon Pink (Lasiodora parahybana) are of the larger species and have been known to produce some 1500-2000 eggs in one sac. Another popular species The Goliath Bird Eater (Theraphosa blondi) however, has been known to produce as little as 50 eggs despite its ‚Äúgoliath‚ÄĚ size.
 Preparationadult female will usually moult every 14-18 months, and so mating should be done before the final 6 months of her cycle to ensure successful courtship. Upon maturing males will lose bulk in their abdomen and legs become long and spindly, this, in addition to the development of Tibial Apophysis, or mating hooks as people like to call them, and boxing gloves, are both an indication that he is ready to produce a sperm web and go on to mate. Some species do not have mating hooks, a list is defined here below see #Tibial Apophysis. He will use the mating hooks to lift the female by her fangs during mating, the boxing gloves are the bulbs where he will store his sperm after creating a sperm web.
Before he is ready to mate the male will need to produce a sperm web, normally made within a couple of weeks of his maturing moult so keep an eye out if you are expecting this to happen. He will produce a hammock shaped web in a corner of his enclosure, usually above the ground rather than inside his burrow. He will then deposit his sperm in the web by a wriggling motion underneath it. To collect the sperm he then walks over the web hammock and if you look closely at his bulbs, you will see his embolus (a small pointed hook) going into the web and taking the sperm from the web. When he is finished with the sperm web, he will usually destroy it, and the sperm is safely stored in his boxing gloves until he finds a female.
 Introducing the Male and Femaleburrow if she is hiding. This technique allows the male and female to sense each other‚Äôs presence and approach each other with caution, preventing any unwanted fights.
He will now begin to act bizarrely, twitching and dipping his abdomen. Drumming is a common mating communication technique used by tarantulas, he will hit the substrate with his front legs and pedipalps, as he approaches the female, and she may reciprocate with some drumming of her own. They are both analysing each other‚Äôs response and deciding if it‚Äôs safe to continue.
When their legs first touch, he will keep tapping and rubbing her legs until she goes into a threat-like posture. His mating hooks attempt to grab a hold of her fangs so that he can lift her up and expose her underside. He will now insert his embolus into her epigastric furrow and deposit his sperm. This process may take a long time, usually a couple of hours will be enough for mating to occur. It is important to keep an eye on them at all times, as you may be required to separate them if a fight breaks out. Do not leave them together for extended periods of time, especially if they do not seem interested with each other, they will irritate each other and the male will probably get eaten. Attempt several introductions aiming to see the insertion of his embolus into her epigastric furrow on at least two occasions, this way you can be sure she takes his sperm to fertilise her eggs.
 Egg sac Productionmoulted. She will need energy she can get for egg sac production, and this means feeding her all the food she will accept. A plumping abdomen is a good sign that she is ready to lay an egg sac and this can be expected around 1-5 months after a successful mating. This duration will change depending upon species, temperature, humidity and other variants such as atmospheric oxygen concentrations.
The signs that she is ready to lay an egg sac are similar to an upcoming moult, which is excessive webbing and refusal of food. At this point you should consider taking a step back and letting nature take its course. Disturbing the female may have devastating results on all the hard work reaching this point, a stressed tarantula will destroy and eat what remains of her egg sac. E. Cyanognathus are a species that will carry the egg sac around, rotating it and massaging it allowing the eggs to grow. As long as the female is carrying the egg sac, she should not be disturbed at all, any disturbance could result in the egg sac being eaten or destroyed. If a female drops the egg sac you may wish to recover it and rear it yourself. Other species such as Pterinochilus murinus will not carry their egg sac with them and will attach it to a suitable covering such as a rock or tree stump. She will choose this location with accordance to their humidity and temperature needs. These eggs do not need massaging or rotating and can be removed from the female, or better the female removed from them to prevent her from eating them.
 Spiderlingseggs should have grown into eggs with legs, and later into nymphs. Finally the nymphs will moult for the second time and out pops a spiderling. You need to take the egg sac from the mother when you suspect that nymphs have hatched. To do this try to isolate the female from the sac using a cup.
Cannibalism is common in tarantulas but rare between nymphs, so separation is not really necessary until the nymphs have completed the moult into spiderlings. Spiderlings will tolerate each other‚Äôs company for a further 2-3 moults however there will inevitably be some cannibalism. Separate the spiderlings into appropriate containers such as small spice storage jars, pill jars or waxworm tubs.
 After Care
It is possible for the female to lay a second egg sac so she must be fed well and left to rest. If a second egg sac is not produced she will probably moult and in which case lose what remains of the male‚Äôs sperm. She can now regain strength and prepare for another mating, or a happy retirement.