Bees have haemolymph which acts in much the same way as mammalian haemoglobin
or blood. The biggest difference is that it doesn't carry oxygen as blood
does and is not contained in tubes. Blood pressure in bees helps keep the body
in shape, which is another difference to us. It carries food and waste
products around the body as needed which is similar. I don't know how much
detail is needed but this is a start. Come back if you need more.
Chris Slade