We got our pet tarantula in November, and named her Grace. She was a lot of fun to watch when she ate (crickets and moths, mostly), and my daughter found her fascinating. Christmas rolled around, and as we made preparations to fly to Virginia to visit my parents, we realized that we needed to find someone to look after Grace. Tarantulas require warmth, and we didn't want to leave the heater running the whole time we were gone.
With some coaxing, we convinced my in-laws to keep Grace at their house. As devout Catholics, they no doubt suspected that harboring a giant arachnid in their home was, if not a sin, at least something that the Virgin would frown upon; but in the spirit of charity they finally agreed. Reassuring them that they would not be required to feed or handle Grace helped too, I'm sure.
So we bought Grace a half-dozen big, juicy crickets and tucked her terrarium away in a seldom-used room of their house.
Perhaps out of concern, or perhaps out of fear, my mother-in-law looked in on her each morning before she left and each evening when she returned from work. Grace didn't seem to be eating any of her six-legged snacks. One morning, she was horrified to see Grace lying on her back, legs in the air. She was running late, however, and didn't investigate. When she returned home, Grace was still lying supine.
Fearing for the worst, she decided to poke the tarantula to see if it were really dead. She tapped on the side of the terrarium. Nothing. She was afraid to open the lid, so she found a long, thin piece of wire in the garage, threded it through the air vent, and tentatively prodded the spider. Still nothing.
When my father-in-law came home, she told him the news: Grace had died. We would surely be heartbroken, she worried, and maybe even angry. Ever pragmatic, he decided to investigate.
"Do they have one spider, or two?" my father-in-law called.
"Um, one..." she replied.
"Well, it looks like two to me!"
Grace had molted-- literally crawled out of her skin. We (finally) got a phone call that evening telling us about it.
The danger was that, as her exoskeleton needed time to harden and she was weakened by the ordeal (you would be, too), there was a risk of Grace being eaten by her own dinner. There was no way to get the crickets out, so they had to be fed lettuce and water until Grace grew strong enough to devour them.
We didn't know it at the time, but nature had already solved the prey-preying-on-the-predator-problem for tarantulas. Grace was lying in a bed of her own web, woven through with strands of highly poisonous (to insects) hairs from her abdomen. She recovered in her own time, then broke her fast on the fattened crickets.
I've decided that I want a new skin for Christmas this year, too.