Hi everyone I recently posted about my duckling (4weeks old) makes a weird tweet sound an everyone told me it was a boy but today he has started limping, he is eating fine an drinking fine just cant tweet properly and now won't walk an when I push it it limps around the brooder. Also my other duckling is the same age an has lost its appetite. The other two are absolutely fine and very out going but the other two seem to be ill to me. I'm new to owning ducks so I'm looking for some good advice on what to do,could this be due to worms why they're acting different? should I worm them?