Sometimes it does not involve chickens and sometimes it does not involve animals at all
Some will not generally keep chickens IN - if that is required then use the Chicken nets (Ultimate Tall Fox Kit or Standard Poultry Kits.) In every other case the Livestok or general Fox nets will be adequate.
The True fox nets will keep out foxes very effectively. They are available in either 145 cm or 110 cm tall nets. The choice is yours.
The energisers will operate with either 12 volt battery or 220 volt mains.