scratching your head than hiding under your seat 
(ROOT (S (S (VP (VBG scratching) (NP (PRP$ your) (NN head)))) (PP (IN than) (S (VP (VBG hiding) (PP (IN under) (NP (PRP$ your) (NN seat))))))))
(ROOT (S (S (VP (VBG ) (NP (PRP$ ) (NN )))) (PP (IN ) (S (VP (VBG ) (PP (IN ) (NP (PRP$ ) (NN ))))))))