Flexible rod-like structures such as nanotubes and nanowires have found significant interest in nanoelectronic applications. Likewise, with the recent advancement in soft robotics and additive manufacturing, an important goal is to optimally design architected slender metamaterials and further derive their effective mechanical properties through homogenization techniques. However, modeling such structures as a flexible continuum body poses multiscale challenges. Lately, there is also a surge in interest for understanding the motion and deformation of such slender structures in the presence of surrounding fluid or external electric/magnetic field. In this talk, I will touch upon the mechanics and numerical challenges faced while addressing the above mentioned problems.