Learning Resources Birds in a Nest Sorting Set. This fun, hands-on, bird-themed activity set supports a variety of early maths skills including colour recognition, matching, sorting and counting. Engaging sorting set features six different colours: green, blue, purple, yellow, orange and red. Includes six nests, six mummy birds, 24 baby birds and multlingual activity guide. Largest piece (nest) measures 8.5cm D x 2.5cm H. Suitable for ages 3+.