A chicken could be described as a two-legged, feathered pig so... do not let them near expanded polystyrene! They will consume it like bread and, given the chance, will also eat small snakes, slow worms, lizards, frogs, toads and newts.
Hens are onmivores and need protein which helps fuel the bird and charge the yolk ready for the life that would normally develop within - so it benefits us too.
So what should you feed your birds? They love and need variety; a good basis is mixed con complemented by mash (not the dry meal sold as mash). I know people who feed this intangible dust to their birds and wonder why it is scratched out all over the place, hens get eye infections, boredom leads to feather pecking, wild bird and vermin infestations and sour soil. One source of protein is insects, slugs and snails, worms, wood lice, earwigs and the like. This is where they derive Omega 6.
They also love green stuff and any fruit trimmings, apple and pear cores, old grapes are a favourite, tomato and lettuce trimmings, cabbage leaves, goose grass, chickweed, dandelions, etc, in fact when weeding the garden throw all the weeds into the run and watch your charges thoroughly investigate all donations.
Hens also love fish, with a local fish stall vendor I swap eggs for fish trimmings, then boil down to make mash, then mix with meal and they love it.
Tired cat or dog food can go into mash, any thrown in to the waste disposal will encourage rats, and, while on the subject, do not leave any unused food out overnight, put it away safelu and remember to elevate housing to deter vermin setting up home underneath. What about drinkers and feeders? After witnessing the devastation from the gales when these have been blown over denying birds sustenance, a local inventor has developed a bracket (called Cock ‘O’ Hoop) to suspend these, stopping the wind and hen disputes knocking these over. It also stops mess getting scratched into them isolating the potential of botulism, listeria, and salmonella .
TIP: now that better weather is here please make an effort to complement your birds’ desire to dust bathe; there are shallow trugs and plastic trays available to put wood ash, dry sand and some red mite powder into, watch them relish it!