First of all, with all of these questions you have, you really need to go and get a good book. "The Tarantula Keeper's Guide" by Stanley Schultz will answer about 90% of your questions. It is the tarantula keepers Bible and a must have for any keeper. I think amazon.com has it for less than $15.
Now I'll try to tackle your questions the best I can.
>>how much and how often should i feed it?
All depend on how big it is. Juveniles can be fed 1 small cricket every few days, large adults will need 1 roach or several large crickets once a week. Feeding schedules is just something you have to play with. After a while you get to know your spider and know when they want/don't want more food.
>>also if i go somewhere like a vacation or something like that during the summer can i leave all the lights off for a week without harm or anything else bad happening?
Tarantulas are nocturnal in nature and stay hidden during the day and come out to feed at night. You'll see more activity form them at bedtime than you will during the day, usually. Therefore they don't need a light on their cage at all. As for house lights, yes they can be off, doesn't matter to them.
>>what if any supplaments might a T need?
None, live food and water is all they need.
>>why would you recomend handling them? that may sounnd like i'm afraid to but i'm not i just want to know why you would recomend it.
I enjoy handling my spiders, some keepers recommend against it, for the safety of the spider. They can be injured from falls of a just few inches, and great care must be taken if you do choose to handle them. I recommend the G. aureostriata, because it is a docile T that is not very skittish and would be easier to handle than some other Ts. There are several great Ts for handling that would be a better choice, but you are interested in something larger at the moment.
>>do tarantulas have individual personalities?
Absolutely, within the same species, some Ts will hide all the time, some will stay out in the open, some will lay lots of web, some hardly none at all, some will keep a tidy cage, and some will constantly dig and rearrange their enclosure. Each one is unique.
>>how deep should the substrate be?
Depends on what you keep it in. Ideally is should be deep enough so that the T can reach the top and bottom of the enclosure at the same time if its legs were completely outstretched. This prevents injury if they happen to climb up the tank or hang from the ceiling and then fall.
>>i am looking at a type of scorpion aswell what might be the pros over having a scorpion? i have hardly found any cons for a tarantula exept the VERY slim chance of a bite or having irritating hairs filked at me.
I don't own a scorpion, but if you stick with something like an Emperor scorpion (Pandinus imperator) to start, then it's really no different form having a T. They can pinch and sting, and their venom isn't very strong. Some other species have stronger venom and yes, some can kill you, so you just have to be educated on the species that you buy.
Ready for the next round of questions….
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KJ Vezino
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