Make 1 packet of jelly according to the pack instructions, using half the amount of boiling water, stirring until the jelly has dissolved. Make up the rest with iced water to allow the jelly to set faster.
Divide between 6-8 serving glasses, to half fill them and chill for 1-2 hours until set.
Place jelly bats, worms, etc on top of the set jelly.
Make up the remaining packet of jelly, using iced water as before, to ensure the jelly isn’t warm when you pour it - so the jelly bats don't melt.
Carefully pour the jelly into the glasses and chill for 1-2 hours until set.