A fully executed contract date begins once both parties signed it. In your case, since you signed them first, the date begins when the seller/affixes his signature. However, the delivery of the ratified contract should also be considered. Consult your realtor and a lawyer.
A group of spiders is called a cluster or clutter. Spiders belong to the group of animals called arachnids.
the class of a spider is arachnida. Spiders belong to the aracnid familly along with all the other types of spiders. Spiders are not insects. They are arachnids. So are scorpions, mite, ticks, harvestmen, and many others.