This is a request and not a unwanted advice.

I am a naturalist and i have opinion that keeping such animals/ reptiles/birds have not so good effect on health.

There are instances in US where a 2 year old developed
menengitis and died as he recieved infection from his pet pythons excreta.

Moreover we most of the time we fail to understand the requirements of the pets as they cant speak.
Hence mortality rate of all kinds of pets , exotic and non-exotic are very high.

Its very sad to see a pet dying which becomes a family member after few months of stay.
I have been through such mental agony once and wont advice/ promot keeping pets.

If your kid is interested in crabs or nature show his on TV, books, markets, websites, soft toys etc.

Getting educated in nature and developing sensitivity is more important than having an animal or whole of jungle at your place !

Finally i leave it to an individuals descrition as i am not the authority. Its a request.