Runt of the litter informal
The smallest and weakest member of a group of animals born to the same mother at the same time.
The flock of birds neglected the runts of the litter.
Because it is smaller and weaker than others, a runt in a litter faces obvious disadvantages for survival.
In the wild, runts in the litter are less likely to survive.
If you swallow the bait, you take something that someone offers you, or agree to do something that someone asks you to do without knowing that it is a trick or way of getting something from you.
You can't just do whatever he wants you to do. Don't swallow the bait.