Editor:
It is such a delight to see humming birds at the feeder. I just bought a new one and found a sachet of instant juice mix inside. Poor birds! They would have to deal with toxins like sucrose, sodium benzoate and tartaric acid. I threw it out.
One part cane sugar to three parts water and they will thrive. Just remember to clean the feeders often so that mould does not contaminate them.
P. Foot
Duncan