Achim and Tatjana Hanne say size doesn't matter when it comes to making a difference.
"Mosquitoes are small but you certainly notice when one is in the room with you," says Achim, explaining why he and his sister are calling themselves the "mini mosquitos" as they fundraise for a children's village in South Africa.
Achim (10) and Tatjana (7) are heading to South Africa on a family holiday later this month, and while they are there will be visiting a children's village, a safe home for orphans and vulnerable children, in KwaZulu Natal. The siblings visited South Africa a few years ago and both were shocked by the poverty they witnessed in some areas, especially when they realised how many children were orphans, reliant on the work of villages such as Kwethu to keep them safe, warm and fed.
"We wanted to do something for the children who aren't as lucky as we are," says Tatjana.
We are visiting our great granny when we are in South Africa. These children don't even have a mum or a dad, let alone a great granny.