Excluding the obvious allergy issues. My DS does not have a nut allergy, and loves nuts. However, the FSA website (and everything else it seems!) says:
What to avoid:
Whole or chopped nuts for children under five years old because of the risk of choking. It's a good idea to crush or flake them.
Why are they more likely to choke on nuts than anything else of a similar size? I hope I'm not missing something vital, and potentially endangering ds.