Why is my cat suddenly bringing in 'presents'?

Over the last 3/4 days we have woken up with 3 x dead mice and 1 x dead bird in the kitchen. However, before these recent deliveries, our cat has not brought us anything for about 5 months.

Is this due to mice/birds coming out of their nests due to the warmer weather? Or is our cat just feeling loved up at the moment and wants to show us

More likely breeding season requires parents to be out collecting food more often than normal. Or your cat wants you to eat mice like they do.