Cannot Uninstall two npm Packages

I have installed node-gyp in order to install scrypt using npm. While installing the node-gyp package the following two packages were installed along with it:

101@1.6.3
d@1.0.1

I have tried to remove these two packages, realising that I did not need the node-gyp and scrypt packages, but sudo npm uninstall does not remove them. Would anyone have an explanation for this?

Thank you. J