
Hi, This is an excerpt from a paper on the Yellowjacket:
"The diet of adult yellow jackets consists mainly of food rich in sugars and carbohydrates, such as plant nectar and fruit. Also, foraging adults search for meat that is high in protein, such as insects and fish, which they chew and condition in preparation for larval consumption. The larvae in return secrete a sugary substance that is consumed by the adults. This exchange of food between the adults and larvae is known as trophallaxis.
In late summer and fall, the normal food materials are in short supply, so the yellow jackets scavenge for alternate food sources which many times leads to major conflicts with human activities. Late-season foods include carbonated beverages, juices, candy, ham, bologna, fish, cakes, fruit, vegetables and ice cream. Large numbers of these pesky insects can totally disrupt a picnic and are often a nuisance around homes and outside restaurants. "
It seems when it gets hot they get extra testy too! I would not worry a bit about the chicks getting "eaten"...however I would worry about them getting attacked and stung to death by grumpy insects. I guess in your situation I wouldn't put my ducklings in a situation like that. I would just put them in a safer pen until the weather cools down some and tensions ease off.
Hope all goes well....LQ