I don't handle my spider because she is a "show" spider....meaning I want her to look her absolute best at all times, and handling can be stressful and cause them to flick hairs off of their abdomens. Truth be told, I'm much happier just watching her then handling her...she actually does intimidate me a bit.
However....Rose hairs are not biters. The arachnoboards has a "bite report" section, with a thread for each species, and even though it is an active, bustling forum with thousands of members, many of which have HUNDREDS of tarantulas, there are only six rosie bites listed.
Out of those six bites, only one sounds particularly painful, so I suspect that that person had an allergic reaction. Also, out of the six bites listed, five of them were people trying to pick up a tarantula that was already stressed about something, and the sixth was an example of someone trying to pick up a tarantula improperly. So.....be gentle, be patient, and when a rosie rears up at you when you're reaching for it, heed its warning!
An upset tarantula will rear up its front legs at you, or flick hairs with its back legs, or will sit huddled up with its legs bunched together as tightly as it can get them.
The proper way to pick up a docile T like a Rosie is generally to come down from the top and "cup" them in your hand, or to scoop them up with a cup and let them come out on their own. Putting one hand in front of a T and trying to "bump" it up with the other hand is a REALLY easy way to get nailed....if you startle the T it will jump at what it percieves to be an attacker.....the giant hand right in front of it!!
Some people also recommend gently grasping the T on the sides, between the second and third pair of legs....but if you don't pick the T STRAIGHT UP off the ground it can actually lose legs this way, and it's also a really easy way to acidentally puncture its body, which almost always means death.
Overall the general concensus is that on the rare occasion a rosie bites, the fangs going in doesn't feel like much, and the bite becomes itchy and then slightly sore, like a bruise. I do want to emphasize again though that this is RARE!
Oh, the thread is here if anyone wants to read it....
http://www.arachnoboards.com/ab/showthread.php?t=287
Bookmarks