Tiny robots have been helping researchers study how cli­mate change affects bio­di­ver­sity. Devel­oped by North­eastern Uni­ver­sity sci­en­tist Brian Hel­muth, the “robo­mus­sels” have the shape, size, and color of actual mus­sels, with minia­ture built-in sen­sors that track tem­per­a­tures inside the mussel beds.