Can smooth newts eat blood worms, ive tried mealworms and bloodworms but it doesnt seem at all interested pls help

my baby corns are about 30cm ( i think) when do i start giving them double feeds on pinky's? does anyone have an estimate length guide for when to up their feed? example - 30cm = 1 pinky or 60cm = 2 pinky's i hope this explains what i mean. any suggestions will be a great help, im new at this!

Just worked it out and not including double or triple portions each meal Ive had 271 successful feeds. 11 more tomorrow. Hopeully. Whats Your Totals 1-10 10-50 50-100 100-300 300-500 500-1000 Im making mice extinct LOL