spider nest (spider puting eggs in spider web)

so usually,spiders are mobs that spawn naturally in the wild,there are two types of spiders but,what to do ,when we need cobwebs,but no mineshaft,no abondonned village and other structures,so,what if,spiders could place cobwebs in a time of 20-30 min,and rarelly (i will say 10% not that rare but you see what i mean) spider eggs summon in the cobwebs and spawn in the proximity of the cobweb ,i let you with these infos and you do what you want