Children love to play than sitting idle. Toddlers generally roam around and like to explore things around them.
As a Teacher or facilitator, provide them with a lot of outdoor activity than indoors. If its summer, Take them to walk in nature. While doing so let the child collect dried leaves, fallen seeds, old twigs, flowers and create an Album or Scrap note book.[Later, I will post how to make scrap note book at home in easy method]. Stick these dried leaves, fallen seeds and flowers. It will be a memory and they start loving nature. Even let them play with butterflies, watch ants moving in a straight line, listen to various sounds like birds chirping, squirrel eating nuts. Try to capture in your camera take a print out and the child can paste in the album.
Even they can grow small plants and water it daily. It will be great excitement to watch the plants growing with small leaves emerging from the stem of the plant. You can teach EVS by showing the shapes of the leaves colours of the leaves and if the leaves get dried their colour changing from green to brown. Explain to them how they get food from nature etc.,