Hi I can’t seem to find the answer. Birds nests to attract a bird to lay an egg do I need to attract 10 birds or spot 10 thanks getting old !

It depends on which part of the nest building process you're doing.

To build the nest, you need to attract five different birds, and the next multiple of five you attract of each will add a piece to the nest.

To get the bird into the nest, it has to be a bird which has added to the nest.  The next multiple of ten you attract will sit in the nest.

To get the egg into the nest, you click the nest then click the link to speak to the bird, who will give you a task to spot your next multiple of five of a particular bird.  Once you complete that task, the bird leaves the egg in the nest.

Got it great thanks Tracey

Sarah, I have found the following useful. The nesting birds are in groups of four. If your nesting bird is one of the four, then it's going to request that you spot from that group, even occasionally you might be asked to spot the nesting bird itself.Group 1: Wren, Yellow Wagtail, Chaffinch, Singing Bush Lark
Group 2: Nightingale, Bee Eater, Roadrunner, Waxwing
Group 3: Kingfisher, Oriole, Chickadee, Blue Jay
Group 4: Woodpecker, Magpie, Jackdaw, Crane

For example, for this month, I had a Singing Bush lark nest who requested I spot a multiple of five Wrens. I didn't get twins so after another 10 Singing Bush Larks visited my garden, the 10th nested and asked for Yellow Wagtails.
Good Luck!