Tarantulas in captivity only eat insects. The most common insect is the cricket. They need one or two per week. Some of the larger species might eat six crickets a week. Tarantulas only eat to their needs so there is no need to worry about over feeding them. If the prey is not eaten within a 24 hour span it needs to be removed from the spider's habitat. Do not worry if the tarantula doesn't eat, sometimes they will feast and sometimes they will fast according to their dietary needs.
Tarantulas need a bowl no bigger than 1/2 an inch deep for water. Fresh water should be given daily. They recieve a lot of their moisture needs from their food.
Trantulas do not make any noise and are generally very docile, thus making them more and more popular to keep as a pet. Tarantulas don't particularly like being held, but they are interesting to watch. Handling tarantulas is generally not recommended due to the possibility of accidentally harming the spider. Tarantulas are venomous, however not enough so to be life threatening to a human. A bite will feel like a bee sting and can cause throbbing pain. (Beware of tarantula bites if you are allergic to bee stings.)
Tarantulas need to molt in order to grow. It can happen every month for young tarantulas and once a year or two when they are an adult. During this time they are most vulnerable and may refuse food for weeks or even months.
Do not handle a tarantula for at least a week after a molt and do not feed the spider for at least three days after a molt. Even the smallest of insects can potentially harm a tarantula just coming out of a molt.