The Cast Iron Grid

A dark, slotted iron mountain crossed my path. Stillness. I stopped. Wide eyes locked on the patterned slats encircling a thick tree trunk. Detour around the rough iron rim? Never. I leaned my full weight forward into the rusted metal curve. Clink! My round belly squeezed past the raised ridge, dropping neatly onto the circular iron mesh. Beneath the grid lay dark earth, damp bark, and a perfectly spherical wooden acorn tucked between two bars! A high perch looking right down into hidden ground. Peep?