Like other Arachnids from their home planet they have Humanoid forms as seen here. They are able to transform their bodies to better fit into certian situations, it is useful for certain situations where there may be prejudice against Spider like Beings. Like mentioned in their Arachnid form Description it is practically impossible for most people to determine which one is which. But in their human forms its even harder for some people, like Mica because of her friendship with Emily's Older Sister Sam once studied both girls for over an hour and still got them switched. The girls themselves find it amusing when people try, especially the 3 brothers they have from their own batch, who even as their immediate siblings still confuse them for the other one.
Part 2 of the Wonderful art I got from  Anvitzi I love their pose in this cause it shows how close they are.
Kiki and Lele @ https://aryion.com/g4/user/credxz and myself