In recent times I have had a lot of trouble with rodents eating my newly planted seedlings before they had a chance to really get underway.
I have set traps and baits in order to try and deal with them, but I really don't like doing either of these - you never know what type of un-targeted animal is going to take the bait. Another problem (although its not really a problem) I have in my area is that there is a very large amount of food from fallen fruit available to them ...... population control is difficult :(
I don't want to create a picture that I have rats running around everywhere because that simply isn't the case, but the rats have affected my gardening by often eating my newly planted seedlings.
To overcome this, I have resorted to encircling each seedling with a wire "cage". This has mostly been effective - there have been a small number of times when the cage has been knocked over, but mostly they are doing their job.
So, if you are coming out in the morning to inspect your newly planted seedlings and find that some little visitor has nibbled away at them and left you with next to nothing, consider trying this as a solution.